Is there such a thing as a case that causes fliers?

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John Alexander posted this 21 November 2021

I have heard and read over the years of shooters trying to eliminate fliers by discarding the cases that shot them.  I'm not talking about cases that have gross variations in neck thickness from one side to the other, oversized primer pockets, or other such know defects, but a case that seems OK but is guilty of being present when a flier was shot. 

Although I have heard of discarding such cases, I have never heard of anybody confirming that the case was guilty by seeing if it would shoot out of the group repeatedly. 

Does anybody know of a shooter confirming that an otherwise normal looking case ruins groups and if so any theories what is wrong with such a case.

John

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Bud Hyett posted this 21 November 2021

In short , "No." This was an informal test, more of curiosity than proof. 

Ed Doonan and I went through this many years ago, we had several discussions with a competitive shooter who did this and could not find his reasoning to be solid. He squashed each case that did not work. The problem was his case was gone and could no longer be tested once squashed. 

Setting up a Remington 700 Sporter in .222 Remington Magnum that was a known shooter, we tagged cases and shot them in order calling each shot. Any shot out of the group was set aside and reloaded, then shot again. We indexed them by the headstamp, but the case could still rotate some on the bolt closing.

We shot one box of Sierra 53-grain Hollowpoint Match bullets and I forget the powder. First five-shot and then ten-shot groups with changing shooters as the day progressed, calling each shot. Changing shooters was to in part to eliminate shooter fatigue. 

There were few flyers, this rifle shot well. This, we used the bullets on the edge of the group. There was no established relationship. The case that shot out one time shot in the next time. The case that shot in one time shot out later. 

From this, I now prepare a lot of cases by first inspecting the primer hole, annealing, trimming to uniform length, outside neck turning to .015 wall thickness for both uniformity and to use a bushing neck sizing die. This is a winter project each year. 

Farm boy from Illinois, living in the magical Pacific Northwest

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RicinYakima posted this 21 November 2021

That is much my experience. Benchrest prep the case and unless it is grossly out of spec, it is not the issue. Then it is good for the life of the case. Lapua cases are good from the beginning, in my experience.  

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Little Debbie posted this 21 November 2021

Nope, if I threw out every case that “caused” a flier I’m not sure how much brass I’d have left…………so other than split necks, incipient separations, the occasional odd body crack they all stay in the herd. As Ric says prep the case, and I assign 100 or more to a rifle and I’ll shoot them till it won’t hold a primer if nothing else occurs first. I rarely include neck turning anymore except for a couple rifles that have proven it helps. My shooting skill and bullet casting are the issues, not cartridge cases.

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GWarden posted this 21 November 2021

I will throw a fly in the ointment. I have brought this up in the past on this forum and on a few others and when I do it is pretty much silence or not much agreement. We spend so much time on the equipment issues, but to me one of the biggest is the "shooter". We are the one thing in the whole system that is not consistent each and every shot, I know some will disagree, so for me I am speaking. The list is long on things that we should look at as the shooter. 

I remember in the past there was a fella that always was shooting fantastic results in the military matches. All kind of things were mentioned why he was always winning, and they pointed at his equipment. I replied one time that a lot had to do with a quality shooter. Saw a short reply on the post from him- "thank you". 

It would make an interesting but long post on just the things we as shooters have to do with "accuracy" when shooting. 

enough said, you all have a good day.

bob

Iowa

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MP1886 posted this 21 November 2021

I will throw a fly in the ointment. I have brought this up in the past on this forum and on a few others and when I do it is pretty much silence or not much agreement. We spend so much time on the equipment issues, but to me one of the biggest is the "shooter". We are the one thing in the whole system that is not consistent each and every shot, I know some will disagree, so for me I am speaking. The list is long on things that we should look at as the shooter. 

I remember in the past there was a fella that always was shooting fantastic results in the military matches. All kind of things were mentioned why he was always winning, and they pointed at his equipment. I replied one time that a lot had to do with a quality shooter. Saw a short reply on the post from him- "thank you". 

It would make an interesting but long post on just the things we as shooters have to do with "accuracy" when shooting. 

enough said, you all have a good day.

bob

Iowa

 

I wondered how long it was going to take before someone mentioned the REAL problem. You're 100% correct Bob.  Analogy: take someone back in the day that thought he was the fastest draw in a gunfight.  Then he gets killed, when all along he thought he the best or at least very good.  

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RicinYakima posted this 21 November 2021

Oh NO! The cat is out of the bag now! People are going to start practicing with their match loads and get to be better shooters. 

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Paul Pollard posted this 22 November 2021

John,

Thanks for starting this thread. In discussions with Bob Birmley, he said that a case would shoot well for a time, then stop shooting. He would discard that case and start a new one. Some of this is mentioned in FS 250 and 251, "On the Road to Records." I tried his method several years ago and could find nothing that worked as he said, so I gave up on trying to find the perfect cases.

There was a recent question on Benchrest Central about Creighton Audette's being a benchrest shooter. Speedy Gonzales posted an article from a 1986 Precision Shooting magazine by Audette. He showed targets shot a long range which were with cases with less than .002" wall thickness variation which were much better than the cases which were .004" wall thickness variation. His contention was that uneven wall thickness mattered. He also suggested that the thin part of the case should be oriented at one of the bolt lugs.

That made me wonder if it mattered in 100 and 200 yard cast bullet shooting. I made a fixture to measure case wall thickness. My 300 Lapua 220 Russian cases have been used since 2008 and have about 70 shots on each one. I ran these over my wall thickness gage and separated them into lots of .001, .002, .003 and over .003 thickness.

One other thing that floats around is that fireforming loads for jacketed bullets are somehow more accurate. I guess it's only anecdotal evidence. I fireformed 15 new cases and checked the case thickness. Most were within .001 on wall thickness. The necks on these all measured .014". If they would fit with a bullet seated, I wouldn't even turn these necks.

On measuring the often-shot cases, it felt like the internal probe was running on a gravel road. I borrowed an ultrasonic cleaner to clean the cases outside and inside, to try eliminating the gravel. No luck. They still felt rough and the over .003 variation persisted in these cases. The new cases did not feel rough when measuring.

That's as far as I've gotten so far. I'm pretty sure that John will accuse me of jousting with windmills, but I've done it before. Some people also say that orienting a case does nothing, but Mike Mohler did, and a few of his records still stand.

It may take some time to run this test and I'll report back.

 

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John Carlson posted this 22 November 2021

I have isolated cases that shot "out of the group", just blackened the head with a magic marker.  Then processed and re-loaded with the rest of the group.  Never found a repeat offender let alone a case that consistently produced fliers.  

Rats!  Now I'm going to have to test whether blackening the heads will produce smaller groups.

 

 

John Carlson. CBA Director of Military Competition.

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45 2.1 posted this 22 November 2021

 

Does anybody know of a shooter confirming that an otherwise normal looking case ruins groups and if so any theories what is wrong with such a case.

John

All depends on how the question is viewed, but the basics are uniform case volume, loaded round case neck clearance/alignment and case fit in the chamber.

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MP1886 posted this 22 November 2021

John,

Thanks for starting this thread. In discussions with Bob Birmley, he said that a case would shoot well for a time, then stop shooting. He would discard that case and start a new one. Some of this is mentioned in FS 250 and 251, "On the Road to Records." I tried his method several years ago and could find nothing that worked as he said, so I gave up on trying to find the perfect cases.

There was a recent question on Benchrest Central about Creighton Audette's being a benchrest shooter. Speedy Gonzales posted an article from a 1986 Precision Shooting magazine by Audette. He showed targets shot a long range which were with cases with less than .002" wall thickness variation which were much better than the cases which were .004" wall thickness variation. His contention was that uneven wall thickness mattered. He also suggested that the thin part of the case should be oriented at one of the bolt lugs.

That made me wonder if it mattered in 100 and 200 yard cast bullet shooting. I made a fixture to measure case wall thickness. My 300 Lapua 220 Russian cases have been used since 2008 and have about 70 shots on each one. I ran these over my wall thickness gage and separated them into lots of .001, .002, .003 and over .003 thickness.

One other thing that floats around is that fireforming loads for jacketed bullets are somehow more accurate. I guess it's only anecdotal evidence. I fireformed 15 new cases and checked the case thickness. Most were within .001 on wall thickness. The necks on these all measured .014". If they would fit with a bullet seated, I wouldn't even turn these necks.

On measuring the often-shot cases, it felt like the internal probe was running on a gravel road. I borrowed an ultrasonic cleaner to clean the cases outside and inside, to try eliminating the gravel. No luck. They still felt rough and the over .003 variation persisted in these cases. The new cases did not feel rough when measuring.

That's as far as I've gotten so far. I'm pretty sure that John will accuse me of jousting with windmills, but I've done it before. Some people also say that orienting a case does nothing, but Mike Mohler did, and a few of his records still stand.

It may take some time to run this test and I'll report back.

 

Speedy is a personal friend of mne. Great guy.

 

Did you ever think that the more you fire a case and reload it that it hardens?  When it hardens the neck tension is stronger.  You  or he didn't mention anealing.

 

I feel one of the most important things done to a case to improve accuracy is sorting them by internal case volume.  Weight cases is a total waste of time as the weight difference most the time is put into a case cutting the extractor groove. 

 

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Shopdog posted this 22 November 2021

To answer the thread title;

Yes.

But then when you read the text,there's no way to provide enough testing to give some folks the assurance they would need to form an answer so;

No

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OU812 posted this 22 November 2021

David Tubb says non concentric cases can cause flyers. Especially when shooting jacketed. Non concentric cases that are full length resized and shot in larger factory chambered rifles will throw bullet off axis and wobble more.

Shooting cast is different since bullet should fit strait and tight in throat from the start. I do not know?

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John Alexander posted this 22 November 2021

Thanks to Bud and John -- and Paul after he shoots those sorted cases for experimenting to find things out. I hope we see more of CB shooters doing this sort of thing to find the truth about what counts and what doesn't.

It is also interesting to hear people's opinions or quoting some very good shooter's opinion but that doesn't improve what we know only states what we believe. Just because super shooter does X , believes in it, and wins doesn't mean that X had anything to do with it. None. May have, may not have. Just think of all the things we used to think necessary and now most winners don't do.  Shooting in same order cast. Indexing cases and bullets. Nose pour molds, Annealing gas checks. Using one case. Sorting gas checks by weight, etc. Sorting bullets by weight will eventually join the list -- in about a hundred years.

John

If super shooters proves something is helpful and reports his tests -- that is a whole nuther thing.

John

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MP1886 posted this 23 November 2021

Thanks to Bud and John -- and Paul after he shoots those sorted cases for experimenting to find things out. I hope we see more of CB shooters doing this sort of thing to find the truth about what counts and what doesn't.

It is also interesting to hear people's opinions or quoting some very good shooter's opinion but that doesn't improve what we know only states what we believe. Just because super shooter does X , believes in it, and wins doesn't mean that X had anything to do with it. None. May have, may not have. Just think of all the things we used to think necessary and now most winners don't do.  Shooting in same order cast. Indexing cases and bullets. Nose pour molds, Annealing gas checks. Using one case. Sorting gas checks by weight, etc. Sorting bullets by weight will eventually join the list -- in about a hundred years.

John

 

 

John that has been done many  many moons ago.  It's just that none of you listen or read everything on the subject.  Before you ask I'm not saying who or what reading material.  If you are as old as you are and haven't heard or read it then too bad. BTW  all those "tricks" you just mentioned aren't worth a hoot unless you have a match target cast rifle and can SHOOT!!!

 

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John Alexander posted this 23 November 2021

MP1886: "John that has been done many  many moons ago.  It's just that none of you listen or read everything on the subject.  Before you ask I'm not saying who or what reading material.  If you are as old as you are and haven't heard or read it then too bad. BTW  all those "tricks" you just mentioned aren't worth a hoot unless you have a match target cast rifle and can SHOOT!!! "

I am going to need your help in understanding your post. I am not trying to be dense but I can't see what the heck you are saying.

What is the "that" in your first sentence that has been done many moons ago?

Is the "it" in your fourth sentence the same "it" that I apparently haven't heard about or read? Or a different It?

You have already said you are not going to tell us who the "you" is that you slander as someone who doesn't read or listen or what it is that that they don't read.  So I won't ask.

I'm sure that I'm not the only one who found your post incomprehensible and would appreciate the help.

Thanks.

John

 

I agree that those "tricks" aren't worth a hoot if you can't shoot. And they aren't worth a hoot if you can and most winners  stopped doing them years ago

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Bud Hyett posted this 23 November 2021

Another thought after reading the many replies. We are dealing with an integrated system; ambient temperature, case, barrel, action, chamber, bullet, alloy, sizing, lubricant, etc.. Designing an experiment to isolate the attribute we want to test can be a challenge.

Realizing this, I spend hours in the winter preparing the season's case and then spend the rest of the time casting. Getting uniform bullets is equally important.

As Ric stated, practice is key.

Farm boy from Illinois, living in the magical Pacific Northwest

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OU812 posted this 23 November 2021

Does perfect concentric ammo shoot more accurate than less perfect ammo. Especially in a larger factory chamber/ throat.

Custom target rifles have tighter chambers and neck to help alignment before flight. I believe the less concentric ammo would shoot worse still. This would be a good test for 6mm ppc owners.

Comparing would be easy...and shoot jacketed bullets only.

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OU812 posted this 23 November 2021

What determines if a case is good or bad? Other than concentricity and neck tension. Some cases have more neck tension than others.

I've heard stories of target shooter seating bullet in case with finger pressure before chambering.

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joeb33050 posted this 23 November 2021

Oh NO! The cat is out of the bag now! People are going to start practicing with their match loads and get to be better shooters. 

It takes a lot of careful, attentive shooting to become a capable shooter.

I believe that a capable shooter does not improve with practice. I've been shooting benchrest seriously for 35 years, shot offhand for 25 years. I saw good offhand shooters shoot great scores reliably after layoffs-no shooting- from months to years.

I've been shooting rimfire for the past five years, many thousands of shots. Frequently 3X a week, 100 record shots per. Recently I have fired 50 shots for record per visit. (It ain't the ammo $.) Sunday 50 yards Irons, BSA Martini International, 5-shot, 10 group average = .660". I got to the range at 70; left at 10:00, It takes a long time to shoot carefully.

.660" is about in the middle of my Irons records; I have not improved in a (long) while. Group size and group size average varies widely, always has for me. The hardest thing for me is to stop, let go of the rifle, and wait for a while. The easiest is to yank the trigger and get rid of the damn shot.

So, I do not believe that practice eliminates/reduces fliers once the shooter is capable, if he is careful. Practice helps runners get stronger. Few mathematicians practice adding up columns of numbers. 

joe b. 

  

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RicinYakima posted this 23 November 2021

Practice making the same errors over and over, will not make you better. 

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John Alexander posted this 23 November 2021

Bud Hyett says:

"Another thought after reading the many replies. We are dealing with an integrated system; ambient temperature, case, barrel, action, chamber, bullet, alloy, sizing, lubricant, etc.. Designing an experiment to isolate the attribute we want to test can be a challenge."

Bud, I agree that we are dealing with an integrated system. However, the impossibility of the perfect test shouldn't prevent us from doing perfectly valid testing. Shooters find enough excuses for not doing testing as it is. After all, most of the factors you list can be controlled pretty easily thus isolating the factor we want to test.

John

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MP1886 posted this 23 November 2021

MP1886: "John that has been done many  many moons ago.  It's just that none of you listen or read everything on the subject.  Before you ask I'm not saying who or what reading material.  If you are as old as you are and haven't heard or read it then too bad. BTW  all those "tricks" you just mentioned aren't worth a hoot unless you have a match target cast rifle and can SHOOT!!! "

I am going to need your help in understanding your post. I am not trying to be dense but I can't see what the heck you are saying.

What is the "that" in your first sentence that has been done many moons ago?

Is the "it" in your fourth sentence the same "it" that I apparently haven't heard about or read? Or a different It?

You have already said you are not going to tell us who the "you" is that you slander as someone who doesn't read or listen or what it is that that they don't read.  So I won't ask.

I'm sure that I'm not the only one who found your post incomprehensible and would appreciate the help.

Thanks.

John

 

I agree that those "tricks" aren't worth a hoot if you can't shoot. And they aren't worth a hoot if you can and most winners  stopped doing them years ago

 

Well I'll try.  There have been knowledegable people that have done what you are looking for and wrote about it.  It's been buried and I doubt anyone is writing about it today.  Thing is many here think there's something new under the sun and there isn't.  

 

Doing all the whistles and bells tricks on cases and reloading for a standard sporting rifle or a mil-surp is going to show up as much as on a purpose built target rifle.  Don't get me wrong  because for cast especially geting the bullet straight into the bore is very important.  For an example deburring the flashhole  for the above mentioned rifles is a waste of time.  So is weighing cases and I explained that in the previous post, but I'll re-address it here.  Have a friend that shoots some highly precial target AR"s.  Even built a highly elaborate rest. Done ALL the so called "tricks".  Mind you he was shooting very well with some very good consistant groups. Then one day he decided to sort his cases by interal volume.  He even built a tool to measure that using alcohol.  Know what happen? He cut his groups in HALF!!   A gun writer went to Hornady's case manufacturing plant.  A Hornady representative was pulling cases off the line where they were almost finished except for the headstamp and extractor groove.  The were weighing those cases and they are unbelievingly very very close in weight.  Consistant.   Then they went to end of the line and weighed cases and they unbelievingly unconsistant!  What's that tell you?  What's that tell you by sorting cases by weight.  That tells me, for one thing, that the weight difference was almost exclusively due to cutting that extractor groove.  Hornady was at the time trying resolve that. 

Weight sorting cast bullets:   If you know how to cast and are a good caster you shouldn't have to do that.  You shouldn't have a weight variance of more then .01 to .03 grains.   Think about it. Say you weight sorted your cast bullets and putting them in little bins and the total weight variance is say 1 1/2 grain and MORE, that tells you that there is definitely a difference between does bullets and that sorting them out by weight or helps accuracy a little, but not as much if all the bullets casted with the weight variance I mentioned above. 

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John Alexander posted this 23 November 2021

OU812 asks:

"What determines if a case is good or bad? Other than concentricity and neck tension. Some cases have more neck tension than others."

====

I can't answer your question. I suspect the correct answer may be -- nothing. That's why I started the thread. Some who think the case is guilty, believe it may be not having perfectly uniform case wall thickness in the BODY of the case. Sinclair and others will sell you an expensive gadget that will allow you to check your cases to ensure that the body, as well as the neck, has uniform wall thickness.However, it seems to me that anybody who considers the violent turbulence inside a case at ignition would be very skeptical.  

Most believers in shooting one case never seem to suggest a mechanism. I was hoping we could scare some up with this thread and see if they seemed make any sense.

Although widely believed, it is doubtful that the two you mention are problems.

Tony Boyer, the best JB benchrest shooter ever, doesn't own a device to check concentricity. Maybe that should be enough said.

Our very own Gerry Bottinger has shown that variations in neck tension from one case to the next have no effect on either the velocity or accuracy of cast bullets. Doubters should read the report of his tests in Fouling Shots #223 and #224.

John 

 

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Paul Pollard posted this 23 November 2021

MP1886 wrote: You shouldn't have a weight variance of more then .01 to .03 grains. 

Is the decimal point in the right place? My one-time best batch had weight variation in 220 bullets of 0.1 grain. Haven’t been that good since then, usually it’s 3 tenths of a grain. And .3 divided by 80 is .375%. 

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MP1886 posted this 23 November 2021

MP1886 wrote: You shouldn't have a weight variance of more then .01 to .03 grains. 

Is the decimal point in the right place? My one-time best batch had weight variation in 220 bullets of 0.1 grain. Haven’t been that good since then, usually it’s 3 tenths of a grain. And .3 divided by 80 is .375%. 

 

I apologize you are of course correct.  I did have the demical in the wrong place. 

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John Alexander posted this 23 November 2021

MP1886,

Thank you for responding to my request for clarification.

I had read your earlier post  about the weight variation in Hornady cases being very uniform before the groove and headstamps were done -- very interesting.

The work of your friend who claimed that sorting his cases by internal volume reduced his groups by 50% is also interesting. Did he write up his testing so someone else could try to replicate his results?

What percentage variation in internal volume did he find? Do you know how many unsorted groups and how many sorted groups were fired in the comparison. 

I'm suspect that Glenn would be eager to publish a report on his work in the Fouling Shot so others could benefit since the results are so amazing. We all would like to reduce the size of our groups by 50%.

Thank you for any additional information you can offer.

John

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MP1886 posted this 23 November 2021

John I would have to recontact all involved in that.  My one friend, who is also a friend that did the volume checking, told me that the gentle was going to make and sell the voume checking tool, but that never materialized. The gentleman shot many many group and was very active in it.  As to how many in a group I don't know. 

It stands to reason that changes in interal volume change pressure and velocity.  An example would be taking a commerial 30-06 case and a military 30-06 case that we know are thicker. I haven't done this, but I'll bet if you take 5 30-06 cases loaded the same, but four of the cases are commercial and one is a military that the military case should blow the group.  Same if you did 4 military and one commercial case.  

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John Alexander posted this 24 November 2021

I agree that it stands to reason that variation in case capacity would change pressure and velocity.  But it doesn't follow that any change no matter how small will have an effect on accuracy.  It depends on whether the variation is big enough. The commercial cases I have weighed only varied a small percentage. A grain or two of brass represents a very tiny amount of volume compared to the volume of the case. So the variation would be very small making it seem likely that any pressure variation caused by a variation in volume would be in the round off error of the normal variation in pressure of 2,000 - 3,000 psi.  

We have the two cited above cases  that indicate that there aren't bad cases and on the other hand your friend's report of amazing accuracy improvement by sorting. So we have conflicting results. One of more of these tests need to be confirmed by others doing testing. That's why I would like to know enough of your friends test design procedure so I or somebody else could run a test to confirm the results.

John

 

 

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RicinYakima posted this 24 November 2021

"Peer review" is an important part of the scientific process. Like all the wrong cold fusion reports over the last fifty years. 

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45 2.1 posted this 24 November 2021

"Peer review" is an important part of the scientific process. Like all the wrong cold fusion reports over the last fifty years. 

Funny how "Peer Review" works. As long as it agrees with the current party line, you get approved of and lauded with praise. You introduce different findings based on evidence that's out side of that party line and you get attacked and discredited. The common term for this is "OOP"  attached to your field of study. The "OOP" means "out of place" that crosses that current party line thought process. It happens in a multitude of places.... EVEN HERE.

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TRKakaCatWhisperer posted this 24 November 2021

"Peer review" is an important part of the scientific process. Like all the wrong cold fusion reports over the last fifty years. 

Funny how "Peer Review" works. As long as it agrees with the current party line, you get approved of and lauded with praise. You introduce different findings based on evidence that's out side of that party line and you get attacked and discredited. The common term for this is "OOP"  attached to your field of study. The "OOP" means "out of place" that crosses that current party line thought process. It happens in a multitude of places.... EVEN HERE.

 

On the flip side, if a procedure is repeatable by others there is a greater confidence in it.

 

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45 2.1 posted this 24 November 2021

True, but someone has to try it...... and learn how to do it. Loading procedure has much to do with attaining the desired results and most everybody's is different. I haven't seen any discourse about how (let's interject some fairly unbelievable results here) it was done....have you?

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John Alexander posted this 24 November 2021

I agree with Ric  peer review before a paper is published along with other investigators replicating the experiment in question afterwards to either confirm or cast doubt on the results is how it has to work -- and does work most of the time in science and engineering. 

But I also agree with 45 2.1 that because human nature is like it is, there have been shameful instances of the conventional wisdom being defended blindly by most of a profession against results that challenges that old accepted wisdom with new evidence. One notorious example is the man who discovered that the movement of tectonic plates is fundamental in understanding the earth's geology spent most of his life before the profession of geology accepted it as truth, or at least the truth until new evidence proves otherwise.

Let's be honest, we in the cast bullet hobby/sport don't have peer review because we don't have an organization to manage it.  We also have little to none of the replication of experiments to confirm or deny the results of experiments after something challenging the conventional beliefs is published. There are many reasons we don't.  The main one is that there is a shortage of shooters that want to contribute.  Many shooters seem to just dismiss the uncomfortable results if it doesn't agree with what they already believe.

Other reasons include that results reported on the internet seldom include enough details for someone to replicate the work-- even roughly.  Articles published in TFS often include enough details and we do occasionally get articles sort of replicating an experiment published earlier. We could do much more and maybe that 0.5 Moa barrier could be cracked.

We have a start right here. We have two studies that failed to prove that there is such a thing as a case that enlarges groups and one that found sorting by case volume reduced groups by 50%.  The only way to find why the difference is more testing. Sorting by case volume is now on my to do list but so are a dozen other projects.  Anybody else interested?

John

 

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MP1886 posted this 24 November 2021

Well John I would tell you that myself and one other member here have broken that .5 moa barrier, but then I'm also going to deny it because he or I are not going to put up with the BS from peers here, nor are we going to come to their range and shoot those groups because they will say they would have to see it to believe it.  We also won't provide target pictures because those also are not believed and I'm not joing the CBA and shooting in matches to prove it. Basically internet gun forums are a very vicious place to be. 

I like that one sentence you wrote: Other reasons include that results reported on the internet seldom include enough details for someone to replicate the work-- even roughly.................Does that include the RPM Threshold Theory? 

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John Alexander posted this 25 November 2021

MP1886,

Congratulations on being able to break what I called the 0.5 moa barrier I wasn't aware of it.

The sentence you liked in my last post was meant to apply to all cast bullet claims and results including the one you asked and  your claim above.  Making claims without the details of how the shooter did it or other proof doesn't. help us learn more about CB shooting.

John

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OU812 posted this 25 November 2021

I bet or guess Tony B. fire forms cases and turns case necks. It is very easy to tell if a case is not concentric when turning necks...high and low spots will show easily.

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MP1886 posted this 25 November 2021

I bet or guess Tony B. fire forms cases and turns case necks. It is very easy to tell if a case is not concentric when turning necks...high and low spots will show easily.
Did you mean the necks be concentric rather then the "case".   Pretty hard to tell if the case body isn't concentric.  I do know a way though.

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OU812 posted this 25 November 2021

The two go hand in hand don't they? If the case wall has a thin side, the neck is thin on same side? Isn't it?

I have the neco case runout gauge.

Again, case runout is critical when full length resizing and shooting in larger factory chambered rifles (especially automatic rifles when case has to be full length resized to feed reliable) Not so much in bolt rifles after case is fireformed to chamber and necks are turned. Sorry for my ignorance or not knowing.

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MP1886 posted this 25 November 2021

I meThe two go hand in hand don't they? If the case wall has a thin side, the neck is thin on same side? Isn't it? I have the neco case runout gauge. Again, case runout is critical when full length resizing and shooting in larger factory chambered rifles (especially automatic rifles when case has to be full length resized to feed reliable) Not so much in bolt rifles after case is fireformed to chamber and necks are turned. Sorry for my ignorance or not knowing.
I don't own the neco. Before I go on has the neco runout gauge made your loads (mainly cast)  "noticeably" more accurate?
If you fire a case at least 3-4 times to finally gets to the shape of the chamber, your outer surface of the case body is going to take on the shape of that chamber no matter what the wall thickest is.  The gas pressure inside the case doesn't recognize that minute thickness difference. If your chamber  is straight how can the neck be out of alignment especially if it was cut with a straight accurater chamber reamer.  One end or other on the reamer would have to be off the centerline when the actually reaming took place. This amount of difference in the body wall thickness isn't going to make enough difference to be worth while doing it. I don't agree that the thin side of the neck is on the thin side of the case body. Do you have examples of that?
I mentioned in a previous post  about a fellow that made his case walls a uniform thickness.  It was on 308 cases. He would expand out the case to a straight cylinder and he would then turn them to a uniform thickness. Seems a lot of work to me. 
Final note is I shoot the small groups without doing very much of the things we have discussed here. 

 

 

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OU812 posted this 25 November 2021

OK you win😷

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MP1886 posted this 25 November 2021

OK you win😷
OU, oh no no, don't be that way.  I didn't say that I was incapable of learning something new.  I thought I might get that out of you.  Get back in the discussion.  I want to know about the neco.  How long you've had, how often you use, etc.  How does it work measuring the wall thickness?

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OU812 posted this 26 November 2021

I've had mine since 1997 and there should be lots of videos using it on YouTube.

I have no proof, but David Tubb says a case that is not concentric will stretch and curve like a banana when fired. Thin side stretches more. Causing bullet to start off axis. Especially cases that are not fire formed to chamber. This was shown in an old Sierra reloading video. I will give you the old vhs video if you want it.

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MP1886 posted this 27 November 2021

OU, first glad you came back.  What you said is interesting.  I'll look at those videos  on the neco.

Tubbs knew that AR's are over gassed and he came up with carrier weight to delay the timing on the bolt openning.  That gave time for most all the gas to be gone from the chamber. He never thought about all that weight banging the barrel extension.  The right way to have done it back then was to use an adjustable gas valve.  So basically I'm not too keen of Tubbs knowledge. 

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OU812 posted this 27 November 2021

In the video he gave a most interesting lecture about cartridge cases. He and Sierra video is the reason I purchased the neco and Sinclair neck turning tool. I mounted my neck tool in cordless drill to help job go faster.

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OU812 posted this 27 November 2021

Midway sells the video. This video got me started in precision shooting.

" High-power Rifle Reloading with G. David Tubb"

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MP1886 posted this 28 November 2021

I watched that video and all I can say I don't think the case is rigidly supported enough to get a accurate measurement.  Especially the head of the case.  The case just hangs on those or that mandrel and by the way he puts them on so easily they can't be snug enough inside the case mouth to be accurate.  Take a Forster neck turner used on it's case trimmer setup.  When turning neck the little lathe like tool cutter has to press on the outside of the neck to cut it right? So which to you think you would get a more accurate consistant neck wall thickness, one where the mandrel is loose, or one where the mandrel is snug, but not snug enough that you can't turn the cutter?  This addresses only one issue with that Neco.  Who's to say the case neck is in line with the case centerline? How about the neck wall thickness? Wouldn't you true the case wall thickness first before you attempt to gauge the case wall thickness? I'm sure not plucking my money down on that Neco no matter what David Tubbs or Sierra says.  Besides I'm very satisfied with the groups I'm getting shooting cast without that tool.

For those who want to see the video here it is on youtuble:

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OU812 posted this 28 November 2021

That video is a very abbreviated lesson. Before using the tool you must full length size brass. Use a die with expander ball. Tool checks thickness anywhere on case. Also checks loaded ammo runout. Very simple to use, but expensive.

New brass is much easier to check runout. Dirty carbon fouled brass does not spin easily on manderal.

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OU812 posted this 28 November 2021

I see you are one of those hard headed types that likes to argue.😃

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MP1886 posted this 28 November 2021

Not so much loving to argue, but to really understand things.   Rather then type what I was going to tell you I'll ask you this question. If you measured wall thickness on so many cases and sorted them out by that, and you took cases and sorted them by internal volume, do you think that the groups would be very much similar?  I say this becaue I feel that the sorting by wall thickness is just another way of sorting by volume.  The rest of the stuff about the case acting like a banana in the chamger I'm not buying.  Last question did using the Neco substantially shrink your group size? Talking cast here.  

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OU812 posted this 01 December 2021

I use Lapua brass and most of it is under .003 runout. I just turned the necks. Shooting cast is a different animal. I use fire formed brass that is neck sized only in the Lee sizer. Cast Bullet fit is very important.

I do believe concentric brass helps accuracy in automatic rifles, but I have no proof.

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MP1886 posted this 01 December 2021

I use Lapua brass and most of it is under .003 runout. I just turned the necks. Shooting cast is a different animal. I use fire formed brass that is neck sized only in the Lee sizer. Cast Bullet fit is very important. I do believe concentric brass helps accuracy in automatic rifles, but I have no proof.
You're talking about the collet sizers....use them myself.  I think they are dang good.  
Well to test what you're talking about requires a subperb rifle and good shooter and a lot of shooting!  Hey that's the name of the game isn't, getting to shoot!

 

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GWarden posted this 05 December 2021

So if one does all these things to try and eliminate flyers, what good do they do if the fella/gal doing the shooting is not a accomplished consistent rifleman?  Been shooting with a group of what I would consider above average shooters, in fact one recently broke a 44 year record in a match this last summer. These three shooters all fired the same rifle, when you looked at the targets shot,  it was obvious not just one shooter shot the targets. So what does that prove, take the person that shot the largest groups and get ride of them? Sorry, I'm getting a bit "snarky". What can we do in this group to help each other improve, isn't that the purpose of it all. 

Back to my original thought on this subject, I feel most times the flyer is shooter induced.  Anyway that applies most times to this shooter.

So, John A. contacted me about maybe starting some post on factors that the shooter can do to improve their shooting. Will give it go. Maybe a recent post on wind flags is one of those issues. 

Bob

Iowa

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John Alexander posted this 17 December 2021

This has been an interesting thread for me although we didn't turn up too many shooting experiments to show if there is such a thing as a bad case as far as accuracy is concerned.  Two posters had given it a try and failed to find a case that caused trouble.  We heard of a shooter who had reduced his groups by 50% by sorting by measured case volume.  So we need more testing to sort it out.

I thought I would get a start on it by sorting cases by volume  and then shooting groups with very uniform volumes against groups using cases that varied by volume. I finally got started today. To measure volumes I put a fired case on the balance and zeroed the balance.  I then filled the case by setting the measure to drop just enough ball powder to run the case over a bit.  Then struck off the powder above the mouth and weighted the filled case.

To confirm that this method would give valid results I measured the volume of the same case over and over again. After ten repetitions I stopped because I got virtually the same answer each time. The highest weight of powder was 20.1 and the lowest was 20.0 (the case was a plain vanilla, 223 Remington). I then weighed ten empty cases and found the range from lightest to heaviest was 2.3 grains.

Next I measured the amount of the ball powder each of the ten would hold and found that range of this stand-in measure for volume had a range of from light to heavy of 0.2 grains. This is only one batch of cases but it tends to confirm the story about Hornady cases posted by MP 1886 and pasted below. If this holds true of other cases (I intend to find out) it means that almost all the weight variation of cases is in the machining on the rear end and has nothing to do with case volume.  Thus sorting cases by weight is an absolute waste of time because that weight has nothing to do with case volume.

The other thing this short test seems to indicate is that the volumes of ordinary mine run cases are amazingly uniform O.2 / 20 or 1.0 percent variation.  More testing of other lots of cases is needed to confirm (or reject) this finding. But if true, it is impossible for me to see how sorting cases by volume could have a measurable effect on velocity or accuracy when the chamber pressure is varying 5 to 10 percent with every shot, This unavoidable variation would totally overshadow the tiny effect of small variation in case volume.

I invite others to do the same for a string of cases and see if the volume is usually so uniform.

John

-----------

MP 1886 posted: A gun writer went to Hornady's case manufacturing plant.  A Hornady representative was pulling cases off the line where they were almost finished except for the headstamp and extractor groove.  The were weighing those cases and they are unbelievingly very very close in weight.  Consistant.   Then they went to end of the line and weighed cases and they unbelievingly unconsistant!  

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MP1886 posted this 17 December 2021

John althought filling the cased with ball powder to measure volume was a noble attempt, as they say no cigar!.  You have to do it with a fluid. The fellow I mentioned uses alcohol.  Now Lane Pearce just recently wrote an article about weighing cases and volume checking them and  there were definite velocity differences between them.  Could it be that one of the different velocity cases got thrown in with a good batch of cases that were all damn near the same weight and volume and throw the shot out of the group?  I believe he proved what we're talking about. 

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John Alexander posted this 17 December 2021

MP1886,

Where is it written on a clay tablet that you can't measure the volume of irregular shaped voids with  fine grained solid material like sand or a ball powder?  It is done all the time in science and engineering work. It is a proven method and superior to using a liquid in some cases. There are ASTM standard procedures written for some of these tests. 

I have only checked one, ten case, sample from one lot of brass, so I am not claiming that there is never any variation in the volumes of  cases.  It would be reasonable to assume that there surely is variation in mixed lots, especially if the lot included some  military cases which often have thicker walls. 

Of course if you want to know the volume in terms of volume units (quarts, cubic meters etc.) you have to find the density of the fine grain solid and calculate the volume in those units just as you have to do with a liquid.  But there is no reason to do this conversion to find the relative volumes of cases. I will probably do this later just out of curiosity but it's not needed to answer the question -- " in a run of typical unmixed cases is there enough variation in volume, from case to case to affect group size?"

I would appreciate it if you could tell me where I could find the Lane Pearce article. I have forgotten what magazine he writes for.  Thanks.

John

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OU812 posted this 17 December 2021

I thought it was proven years ago that thicker military brass can raise pressures drastically. Probably not so much using TiteGroup powder, but bulkier case filling powders you will see differences.

A test of case runout ( more concentric vs less). I have checked various brands of 223 case runout using the neco gauge and Remington brand varied the most from .001 to .007". Thin side will stretch more when fired .

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John Alexander posted this 17 December 2021

As I noted in my last post, I think it is generally agreed that some (maybe most) military brass has thicker walls, thus a bit less volume leading to higher pressures (not sure about "drastic").

I have a friend who insisted, against my advice, on shooting a collection of brass that included some military brass. He also tended to load max or near max loads (some of his handbooks suggested reducing charges for military brass which he ignored).  It finally caught up with him last summer when one of his hot reloads in a military case blew out the primer and took off the extractor of his Savage 110 type action.  The extractor was easily replaced. No other damage, but I believe he is more cautious. 

It seems to me the important question isn't, is the thickness of the case body uniform? or -- does the thin side stretch more after the case is full length resized and then fired? At least to me, the important question is -- Does it makes any difference in group size? I am very dubious that the expanding gas cares about either, but I'm not sure. Only shooting experiments can provide the answer and we don't like to take the time to do them to find out. Pity.

John

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MP1886 posted this 17 December 2021

John, Lanes article is in the latest Shooting times that just came out.  It's in the Answers and Questions column.  Myself there wassn't enough to the article to satisfy me.  

On using ball powder I merel meant the liquid was a more precise measure, but I'm sure that there are some really fines powders (not cartridge powders) that would get pretty close. 

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John Alexander posted this 17 December 2021

MP1886,

Thanks I will try to scare up a copy of Shooting Times. Subscribed to it until a year or two ago.

It may seem like it would take a very fine powder to measure volumes.  This isn't true.  It depends on the size and shape of the volume.  The bigger the volume and the fewer the sharp corners the bigger the grain size can be.  00 Buck would produce precise results for a gallon sized volume with only rounded corners.  AA #2 which is what I used for the 223 cases works fine. This is shown by it's repeatedly. In ten repetitions of measuring the same case, the measured volume had a range of only 0.05 percent (0.1 / 20). This shows the test is very reliable and very precise. I think one would have to be pretty careful to get similar repeatability with a liquid.

John

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GWarden posted this 18 December 2021

I do lots of shooting the old single shots with the two piece stocks and  breech seating the bullet, so always using the same case. Now if I am always using the same case, checked  bullets for uniformity etc, one would assume there would never be any flyers  by all the  comments presented on this topic.  Well, I still get flyers, but they are not caused by the case,  bullet, etc, it is the fella doing the shooting. For me, it is those lapses that take place (brain fog), that has always been the known reason for this fella's "flyers".

bob

iowa

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JimmyDee posted this 18 December 2021

An article in the June 2021 Handloader (Rifle Case Necks) discussed "donuts" that formed inside the case at the bottom of the neck.

After "cases had been reloaded a few times, 'fliers' started showing up and, eventually, occasional signs of high pressure."  The thought is that brass moved during resizing formed donuts at the top of the bottleneck and pinched the base of bullets.  That caused inconsistent pressures which resulted in fliers.

 Annealing after four loadings helped. Out side neck turning didn't help very much but is important for bullet-to-bore alignment.  He went on to say "an inside neck reamer for my Forster case trimmer cured the problem." 

Cast bullets, too?

 

 

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OU812 posted this 18 December 2021

My cast bullets are never seated deep enough to reach donut area. So maybe donut has no effect on my cast loads?

Too many variables (firearm types and chamberings). It would be easier to learn from each other if we all shot the same model rifle and chambering.

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Shopdog posted this 19 December 2021

A recent new rig required all the parts of the handloading puzzle. Dies,moulds,sizers,everything.

Usually make custom spuds for one of the dz M die bodies but wanted to order another die body. Whilst waiting for it to show up...

Took a piece of 5/16, 8" long O1 and turned the ends with stepped diameters to use,wack a mole style just to get up and running. Ot worked OK,although it's a little figgity. Bought 100 new Lapua 260 cases to be used. Rig is stupid accurate putting 5 into a single hole. But that's not the point here.

In the process of using this surrogate expander,and just confirming neck dimensions coming out fired,I started using this rod in other ways. Obviously checking run out of a fire formed case showed zero.

But when I put the rod,snugly into virgin brass..... and then rolled the rod on a plate,with the brand new case hanging off,not touching the plate....... HOLY MOLY. Figuring out which cases had internal "issues" resulting in crooked necks was or takes less than two seconds.

Even after running the cases into a brand new RCBS FL die,some of these more,"wanged" cases were still suspect. Changing diameters on the ends is easy peasy as we have some pretty "tight" machinery here. Just sayin,the range rod is held to VERY tight tolerances. Make one,and set up one end to firmly fit in a new case and roll it.... you're gonna be surprised at how bad new brass is.

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Paul Pollard posted this 19 December 2021

John A said, "Only shooting experiments can provide the answer and we don't like to take the time to do them to find out. Pity."

I can't shoot in my backyard anymore, so the testing takes more time.  I've only been out two days and the data is a bit thin. So far, nothing stands out. Conditions cause problems, so my data will be aggregates. This limited data would suggest that high runout cases are better.

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John Alexander posted this 19 December 2021

 I love it. Give that man the CBA shooter of the year award.

Instead of sitting around navel gazing about whether we should worry about case thickness or not, or building a fancy tool to measure it more precisely, Paul actually went to the range to find out if it made a any difference.

I especially like it when the "good" cases (or sorted bullets, clean primer pockets, machined flat bases, etc.) seem to make the bigger groups. Of course, as Paul noted, this is just an indication that we need to remember that variation in groups, or even in aggregated, is bigger than we think even in Paul's respectable five 5-shot groups. If we really think about this it should keep us humble about what you can believe when firing only a few groups in your test or looking at one group and assuming it represents the performance of that load.

It should be noted that Paul has worked in an additional value in his testing, without weakening his results about cast thickness, by using two lubes. Very crafty Paul.

As an additional benefit  Paul had a good excuse to go to the range and shoot. Isn't that what we say we like to do?

John

P.S. Paul when you finish your shooting I will be nagging you without mercy to put your results in the Fouling Shot.

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Geargnasher posted this 19 December 2021

A more meaningful experiment is to assemble half the ammunition with .0005" neck tension and the remainder with .002" neck tension, or anneal half the cases and exercise the other half three times through a full-length die, and shoot each lot separately for group size and point of impact.  Overlay the targets for an aggregate.  

Every time it is suggested on this board that case neck tension variance causes POI change, we are beaten about the head and neck with Gerry Bottinger's experiments which is not only tiresome but a most basic logical fallacy because it is insisted that his findings are true in EVERY situation, which they most certainly are not.  No wonder progress here is so slow.  Mr. Bottinger's findings are only true in very specific instances in which the loading methods preclude neck tension being a factor at all, per his articles. 

When sweeping generalizations are accepted as true, you box yourself into a corner and and exclude further avenues of progress.  Like Sheepdog mentioned at the start, yes, a bad case can cause a flyer, but like Sheepdog, I will never be able to produce enough data to satisfy the professional statisticians here.  If you're truly interested in exploring the subject of a "bad" case, try the scenario I outlined in my first paragraph....only seat your bullets .015" off the ball seat. 

Another useful experiment is to take your favorite match load and put them together as normal, only this time use a fish scale or other spring/type scale to gauge bullet seating force and segregate into groups by that criterion in an otherwise identical, large lot (say, 50) of cartridges.  Shoot the segregated lots individually and overlay the groups.  Observe and report.

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MP1886 posted this 19 December 2021

Another useful test is to anneal your case neck after every loading and shooting.   I know a few match shooter that do this and it improved their groups.  First and foremost if you don't have near perfect cast bullets all efforts are useless and I do presume we're talking about cast bullet fliers since this is a cast bullet forum.

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JimmyDee posted this 19 December 2021

Stepped diameters: very good idea.

After reading this thread, I realized that my case preparation, for some rifles, just got a couple more steps.

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John Alexander posted this 19 December 2021

Gearnasher,

I agree that the two experiments you suggest in your first paragraph, along with the one suggested in the last paragraph, would provide useful information. This is exactly the type of work we need in order to begin to bring CB shooting out of it dependence on faith, opinions, and old wives tales and work towards experiment based loading principles.

Have you done your suggested experiments? if so, please let us know how you did them and what the results were. If you haven't done them please try and find time to do them and let us know what you find. I particularly like your suggestion that there should be 50 cases in each condition. That should be enough unless the differences found are very small. By the way, I have an experiment started that is similar to one of the three you suggest.  We can maybe compare notes when done.

I don't think quoting Bottiger's test results is a "logical fallacy" basic or otherwise.  It is quoted because it is the only test we know of that has explored that issue with anything approaching logic.  Anecdotes about doing this or that and thus halving or doubling group sizes are interesting, but usually based on one or two groups and come by word of mouth. There is never enough information to replicate them in order to confirm or refute the claims. We need more evidence than this to make progress. When we get your results on the three experiments you suggest we can examine them along with Bottiger's and see if there are exceptions and what those exceptions might  be.

If we work together on this we will eventually find the important factors and eliminate the unimportant ones for smaller groups with cast bullets.

John

 

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MP1886 posted this 19 December 2021

This from a match shooter and rifle builder. I have to agree with him.

Benchrest has hundreds of nit things that'll drive even the most OCD person nuts. I've found a lot of those things contribute to top precision / accuracy. Some not so much. Most of which are covered in the previous 65 pages. I will say this however.....to shoot towards the top you have to have these four:

1) The ability to read wind and hold-off
2) The ability to tune your rifle and keep it in tune as conditions change
3) A good barrel
4) Great bullets that mesh well with that good barrel.

Fall short on any of those four and you'll be middle of the pack or lower. There's no action, reloading trick, bedding job, front rest / rear bag, scope, trigger, etc, etc, that'll make up the difference.

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RicinYakima posted this 19 December 2021

FWIW: 1950's American Rifleman article on what is most important for accuracy.

1. Bullet center of mass at center of form

2. Bullet size in relationship to groove size

3. Bullet form (shape?)

4. Jacket hardness or thickness variations

5. Powder position within the case

6. Cartridge OAL

7. Bullet weight (2.0 grains moved bullet POI 3/4" at 300 yards)

8. Powder type (stick or ball ?) if appropriate within pressure range

9. Powder weight within 5% 

10. Primer

This is for FA 173 grain match bullets in 30/06 made for match shooting. This was the opinion of George Jacobsen, former Assistant Superintendent of Frankford Arsenal, Philadelphia, Pennsylvania.

We cast bullet shooters have many more factors to contend with than just these. But I think he is correct in principle.

Question marks are my comments. 

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Geargnasher posted this 19 December 2021

John, I only have one semi-benchrest rifle, but have been observing the effects of many things, including case neck tension and annealing, for a long time.  I typically use range pickup brass, or second-hand brass purchased from gun forums, because I am cheap and like to stretch my shooting dollar.  I don't compete, so it doesn't matter to me much.  One thing I have done religiously for many years is sort the "light" or "heavy" seating handle pulls to the side and only use the most uniform for accuracy testing, then shoot the remainder in a separate group to see how much it matters.  I haven't been good about alternating shots and typically shoot the "bad" loads last, but I have done some alternating testing to prove to my own satisfaction that indeed it is case neck tension variances which matter very much.  I don't weigh brass, don't use many of the CBA-standard throating and bumping, never use an alloy more rich than Lyman #2 (and usually much weaker), don't measure internal volume, and almost every rifle bullet I cast anymore gets powder-coated. At most I uniform the neck thickness, deburr flash holes, and uniform the primer pocket depth because RemchesterFederal is not very good in these departments.   So I'm not your guy, but I can certainly tell you that the difference between a 7/8" group ten shot group and 7 in the same core group but totaling 1.5" due to three flyers can easily boil down to bullet pull consistency.   You guys who can shoot better than me and have the rigs can devise the statistically valid tests and prove the difference with percentages very easily.

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OU812 posted this 19 December 2021

A better test would be compaire most concentric (.000-.002) neck turned brass to less concentric (.004-.005) unturned brass. This test would have to be done with loose neck chamber area so unturned case will fit chamber.

If your cast bullets fit throat perfect like a snug glove, you will see little accuracy difference...I think?

Correctly Fitting the cast bullet to throat is way more important than case variation. Big changes (not little) in testing will prove . But I have no proof.....

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Paul Pollard posted this 20 December 2021

John A.

This test started badly. The reason for the lube change was that the first 3 groups of the first day opened up to 5 inches. Brushing and swabbing throughout the test barely kept the groups reasonable. The second day with the lube change was not much better. I had to swab the barrel after each group. It looked like heavy powder fouling, not leading. There were also several bullets which eluded the sizing die and could not be shot. Another well-planned test derailed!

I will be continuing with the less meaningful test, and using the SS pins case cleaning in conjunction with this test. One good thing about failure is that it has me looking at everything again. I need a bigger sheet of paper for all the notes.

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OU812 posted this 20 December 2021

Do all powders leave that hard fouling. You know that hard fouling at first 6 inches inside bore. It would nice to find a good accurate powder that burns cleaner than my Tite Group. I bet some of the newer quick burning powders burn cleaner?

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John Alexander posted this 20 December 2021

MP1886 posted this 22 hours ago

"Another useful test is to anneal your case neck after every loading and shooting.   I know a few match shooter that do this and it improved their groups.  First and foremost if you don't have near perfect cast bullets all efforts are useless and I do presume we're talking about cast bullet fliers since this is a cast bullet forum."

=====

MP1886, 

It is interesting that some match shooters do this and believe it improves their groups. However, this comes as an interesting second hand anecodote until me know more about the details. I agree with you, a test to pin this down would provide useful information and possibly lead to smaller groups.

If you haven't done this test please try and find time to run it and let us know what you find. Your results would be a good contribution to what we know.

I don't know why you think you have to have near perfect bullets to run a good test but at any rate near perfect bullets are easy to cast so that shouldn't be a problem.

Thanks for your suggestion.

John

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Ken Campbell Iowa posted this 20 December 2021

Pauls comments on failed test attempts reminded me

that one of the big ( another big ) mysteries to me about cast is 

how the heck can i get 8 inch cast groups from a one inch rifle ( with mj ) with castings that look pretty good, fit that is pretty good, and clean or fouled barrel ......  and yeah, i can shoot 8 inch groups offhand with mj in it ... i do have bad shooter days, but they never get that bad ...

i think our 2.0 groups are just smaller horrible 8 inch groups.

i wonder what causes them ?? ...  

 

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MP1886 posted this 20 December 2021

MP1886 posted this 22 hours ago

"Another useful test is to anneal your case neck after every loading and shooting.   I know a few match shooter that do this and it improved their groups.  First and foremost if you don't have near perfect cast bullets all efforts are useless and I do presume we're talking about cast bullet fliers since this is a cast bullet forum."

=====

MP1886, 

It is interesting that some match shooters do this and believe it improves their groups. However, this comes as an interesting second hand anecodote until me know more about the details. I agree with you, a test to pin this down would provide useful information and possibly lead to smaller groups.

If you haven't done this test please try and find time to run it and let us know what you find. Your results would be a good contribution to what we know.

I don't know why you think you have to have near perfect bullets to run a good test but at any rate near perfect bullets are easy to cast so that shouldn't be a problem.

Thanks for your suggestion.

John

 

John I must admit that keep some reject cast bullets that don't look too bad for just fooling around or for testing a velocity of a load while exprimenting.  On doing test with them, well there are certain defects that can really open up a group. These would be the ones inside the bullet that you cannot see.  I especially now with the state the country is in about componants I don't like to waste what I have.  Like that match shooter pointed out the main things that cause bad groups the most perfect bullets are preferred and  I would think that would hold true in cast bullets too.  Once you have your casting technique perfected you won't weigh bullets anymore  if you previously did so. BTW the way some of those rejects shoot predecent.

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Paul Pollard posted this 10 January 2022

Here's an update on the case wall thickness test. I could find no evidence of a correlation in variation of the wall and bigger groups. It was pretty much the opposite. On Day 3, I cleaned before each group and shot one fouler before the group. The fouler shot was shot on a separate target. I then had 5 fouler shots for a group. The results are in the table.

Table of Groups

I have concluded this test for now. It may take a better shooter and analyst than I am.

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John Alexander posted this 10 January 2022

Paul,

Outstanding! There is nothing wrong with your shooting or your analysis.  First rate experiment with a side benefit of taking a look at the precision of fouling shots.

Some time ago the jacketed bullet benchrest community had their collective knickers in a twist over non uniform case wall thickness. Theories were ginned up about all the bad things that might be caused by such case defects. All this speculation and angst was dully reported in their journal "Precision Shooting".  A ton of high priced case wall thickness measuring devices were sold. Shooters were indexing cases so the fat side was always on top or bottom when chambered. NOT ONCE did I see a report like yours of a logical designed experiment to confirm or refute the theories.

That silliness is a prime example of what happens when we try to reason up a theory about shooting without making sure our assumptions are correct. In this case anybody who had paid attention in high school physics would have known that gas in a closed container i.e. case, exerts pressure equally in all directions.  Thus the pressure on the base of the bullet wouldn't be affected by the shape or size of the case. And thinking that the case body needed to be concentric with the bullet base is beyond all reason.

Congratulations Paul on some first rate work. I hope you already have it written up for TFS.

John

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45 2.1 posted this 10 January 2022

 

 In this case anybody who had paid attention in high school physics would have known that gas in a closed container i.e. case, exerts pressure equally in all directions.  Thus the pressure on the base of the bullet wouldn't be affected by the shape or size of the case. And thinking that the case body needed to be concentric with the bullet base is beyond all reason.

.John

The lab guys tell us that those pressure waves rebound back and forth inside the case. A very dynamic situation. What does that behavior do to a non concentric case, let alone steep shoulders on the case?

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freebullet posted this 11 January 2022

In my experience those cases with neck thickness issues will cause fliers.

I don't waste time turning necks for that issue because it was explained that variation runs the length of the case. Turning the neck doesn't correct the rest of the case. The book explains it like a banana shaped case. Makes sense to me it wouldn't heat or respond to heat/pressure the same.

Since following that advise helped, I haven't looked back. Ymmv

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John Alexander posted this 11 January 2022

The situation inside the case as the bullet is starting to move is surely far more complicated that a static pressure situation. There is bound to be the pressure waves you mentioned in addition to tremendous turbulence for any shape case. This state of unpredictable chaos seems even more reason to be skeptical that a 0.003" difference in wall thickness could possibly affect the pressure on the base of the bullet. Our opinions may differ on this but neither opinion makes a whit of difference.

Until someone performs an experiment similar to Paul's that shows that there is a correlation between uniformity of case wall thickness and accuracy, we have Paul's results versus a lot of hot air.

John

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OU812 posted this 11 January 2022

Most everything from Cast Boolits is hot air I think.

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45 2.1 posted this 11 January 2022

Until someone performs an experiment similar to Paul's that shows that there is a correlation between uniformity of case wall thickness and accuracy, we have Paul's results versus a lot of hot air.   John

It's been a long time, but Merril Martin did this exact thing in a 30-06 cast bullet match rifle by turning the case body's walls to uniform thickness. Look it up yourself in Precision Shooting.

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John Alexander posted this 11 January 2022

So -- why don't you reveal what Martin found?  What happened after he turned the walls to uniform thickness? That would be helpful instead of just a cryptic shot.  I'm sure that very few of our readers have a file of Merril Martin articles at their fingertips. 

John

 

 

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Ken Campbell Iowa posted this 11 January 2022

i understood the brass case wall thickness difference to affect >>

the way the case head affected the bolt face .... one lug being struck harder than the other from case head impact ...and thus.>

the vibration of the gun and thus where the barrel pointed at barrel exit.

***************

seems silly but then i recall a popular improvement for Remmy 700 actions is to install an oversize bolt ($500)  so it can be " blueprinted " tight and true to the locking lugs and chamber.

and even some cheep-arse crutch fixes that involved brass shimming the rear of the bolt body and also just installing a cap screw through the top of the rear ring to keep the back of the bolt from tilting as the cartridge is fired. ( and maybe because of the trigger design ) ...

**************

could be ... from my 22rf and barrel tuner days i BELIEVE in those vibration conspiracy theories ... we could get a 1 to 3 group size difference by moving the tuner ...   

refer to Dan Lilja's little notes on action movement at the shot .. it does stretch due to rear force on the lugs.   will a thin case wall push one bolt lug more than the other ??? ... LEMME SEE THE TARGET !! ...


**********************

finally, ... some of my midwest hero MJ benchresters are having success with a chambering where there is almost no case neck ... the idea is that the bullet is located really well by the case tapered shoulder ... this seems really interesting ...  if the case neck is such a nuisance, just get rid of it ! ...  

of course, about the same idea would be to run loose case necks and seat the bullet in that loose neck with some post-it note glue ... rubber cement.....

i gotta stop, i'm killing myself ...  ken

 

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45 2.1 posted this 11 January 2022

So -- why don't you reveal what Martin found?  What happened after he turned the walls to uniform thickness? That would be helpful instead of just a cryptic shot.  I'm sure that very few of our readers have a file of Merril Martin articles at their fingertips. 

John

I said it's been a long time. Someone (on another forum) got permission to post Merril's write-up from him with pictures and all. I remember the pictures and somewhat of the results (that being it was favorable for him). I don't have any files of his as I didn't take Precision shooting. At the time, I had worked out something else and had no need of his method. If you want more, then you'll have to look it up.

 

 

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John Alexander posted this 11 January 2022

45 2.1,

Thank you.

John

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John Alexander posted this 11 January 2022

Ken,

Interesting ideas. I always thought that the theory that it caused unequal force on bolt lugs the most promising explanations of all the other theories about why it should help -- but it is still just a theory.  

JB shooters seem just as reluctant as CB shooters to take a day, load some with and some without, and shoot a few groups to find out if the theories we like to think up amount to anything. 

I think the panic over case wall thickness has gone the way of indexing cases with JB shooters. In my close reading of 3 books by top JB benchrest  shooters including Tony B's. I found no advice about uniform case thickness.

I like the idea of minimizing the amount of bullet in the case mouth. Part of John Ardito's success may have been that he throated so that his bullets were barely in the neck. I know he thought so.  It seems even more reasonable for CBs than JBs since CBs are much softer. I have tried to design bullets for factory throats so not much more than the gas check is in the case but haven't got it right yet but throat erasion is helping get closer.

John

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shootcast posted this 12 January 2022

We all do things that seem like there should be positive effects. Maybe for some of us there is. If it works or you think it works you will continue to do it. I once read and article that I believe was written by Jim Carmichael. I have never been able to find it so maybe it was someone else. The writer experimented with putting 223 cases inside of 308 cases to effectively reduce case volume. Sounded interesting to me and I tried it also. My outcome was the same as his. Although it worked some small extent or it seemed it did it was not a given. Accuracy on average was no better than using standard 308 cases. Shoot enough groups and occasional you get a dandy.

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RicinYakima posted this 12 January 2022

Yep Jim Carmichel in an early Handloader. Did the same thing as you did, sort of worked but inconsistent. But you could use smaller measures of faster powder and get OK results when powder went in price from $4 a pound to $8 a pound in the 1970's. 

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John Alexander posted this 20 January 2022

I am doing some experimenting on the topic of "bad cases" and in thinking about it could think of these things about A SINGLE CARTRIDGE CASE that might possibly affect group size.

Variation in powder capacity

Variation in neck  wall thickness

Variation in case wall thickness

Variation in neck tension on bullet

Are there other possibilities? Suggestions appreciated.

John

 

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RicinYakima posted this 20 January 2022

Head not square with the case walls, centerline of the bore.

 

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Lee Guthrie posted this 23 January 2022

Think of his diatribe to be more in the nature of "word salad".   His just wasn't as tossed as much as it could have been.

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BJung posted this 27 January 2022

Maybe. I haven't don't a test to verify my claim but read this article from lasc.com. An exceptionally long or short case might contribute to a handgun flyer

Secrets of reloading for the Colt Combat Commander 9MM auto loader (lasc.us)

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OU812 posted this 27 January 2022

Lots of videos on the subject. This author named Bolt Action Reloading has lots of test videos concerning jacketed bullets and F class long range shooting. I gather that bullet fitment inside throat is most important. Loaded round concentricity is OK if under .004"

https://www.youtube.com/c/BoltActionReloading/videos

https://www.youtube.com/c/BoltActionReloading/videos

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