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

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John Alexander posted this 2 weeks ago

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 2 weeks ago

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 2 weeks ago

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 2 weeks ago

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 2 weeks ago

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 2 weeks ago

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 2 weeks ago

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 2 weeks ago

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 2 weeks ago

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.

 

 

Holding public office should be viewed as an obligation to serve, not an opportunity to rule.

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45 2.1 posted this 2 weeks ago

 

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 2 weeks ago

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 2 weeks ago

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 2 weeks ago

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 2 weeks ago

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 2 weeks ago

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 2 weeks ago

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 2 weeks ago

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 2 weeks ago

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 2 weeks ago

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 1 weeks ago

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 1 weeks ago

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

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John Alexander posted this 1 weeks ago

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 1 weeks ago

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 1 weeks ago

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 cast 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 the Fouling Shot.

John 

 

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Paul Pollard posted this 1 weeks ago

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 1 weeks ago

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 1 weeks ago

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 1 weeks ago

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 1 weeks ago

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 1 weeks ago

"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 6 days ago

"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 6 days ago

"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 6 days ago

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 6 days ago

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 6 days ago

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 6 days ago

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 6 days ago

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 6 days ago

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 6 days ago

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 5 days ago

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 5 days ago

OK you win😷

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MP1886 posted this 5 days ago

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 4 days ago

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 4 days ago

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 4 days ago

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 4 days ago

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 2 days ago

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 2 days ago

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 2 days ago

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

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MP1886 posted this 2 days ago

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 14 minutes ago

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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