First shot flyer's

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  • Last Post 13 November 2007
JDNC posted this 27 October 2007

Hello everybody,  I'm new to this forum and this is my first post.

 I recently have been shooting a LBT 30 cal 170 gr bullet cast of WW and heat treated to about 30 Bhn (LBT Blue lube) in a wildcat with a case capacity somewhat between a 308 and 30/06 (velocity at 2400 fps).  The time between my loading sessions of 10 rnds (as I'm testing loads) my barrel cools for approximately 30 minutes.  When I return to my bench and fire my next string usually my first shot out of a cool fouled barrel is out of my group an inch or less with the following shots less than MOA at 100 yds.  As I do a lot of testing loads (jacketed and cast) I monitor relative pressure levels with an instrument called “Pressure Trace” from RSI and have been doing so for several years now.  I was looking over several pressure traces (five different groups) the other night, when I noticed that every 1st shot trace of every group was approximately 1500-2000 psi higher than the last four shots in the string, when the barrel was cool.  Sometimes the velocity would increase by a small amount (30fps) but very little. My question is,  could this because as my barrel cools between shooting sessions the lube and fouling hardens and causes more friction during the 1st shot?  If so, would a softer or different lube cure the problem?  Am I even on the right track? One thing is for sure in my barrel, the first shot when cool and fouled is higer in pressure and usually my flyer (not always).   I would appreciate input from all. 

Thanks  

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PETE posted this 27 October 2007

JDNC,

  Now that is interesting. I've always wondered why most of my rifles will do the same thing.

  Your thinking on what happens is what I have suspected. As the barrel cools the lube/fouling has a chance to harden, or set up, and the first shot tends to break this up and deposit a fresh, warm, soft layer of lube/fouling. I think your pressure tests would seem to support this idea.

  Since I do all my testing over a chronograph I've also noticed this, as you put it, slight increase in MV with the first shot of a group. This is why when I shoot for a group the first shot or two goes into the sighter bull, and I allow for this by having, say, 6 loads for an intended 5 shot group.

 I had to smile when I saw your reference to an increase of 30 fps as being “small". In the game I mostly shoot (Schuetzen), and at there velocities anything over a variation of about 10 fps will show up on the target at 200 yds.

  The thing that makes this sort of a theory for me is that I do have a coupla guns that will put the first shot into the group whether the gun is hot or cold, clean or fouled.

PETE

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RicinYakima posted this 27 October 2007

JDNC,

I agree with Pete on this line of thought. I, also, have noticed this happening especially in the winter when the air temperature is in the 30's. The only thing I have found that lessens, but not stop, this is to push one dry patch through the barrel. I don't know if it is just pushing excess lube out of the throat, or the whole length, but it does bring the first shot closer to group center. In the summer, with temperatures in the 90's, this doesn't seem to happen.

Ric

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JDNC posted this 27 October 2007

Pete,

Thanks for the input.  I was wondering about changing lubes to see if this would help and was wanting input from you guys.  As for the “small increase in velocity", I guess when I think of the velocities I have with my rolling block with black powder in 45/70 30fps is sort of funny! You're right 30 fps is a great deal with a 550 gr at MV 1250 fps.  I am planning on using this 30 cal. to hunt with and if I can't solve this 1st shot problem I might as well zero the rifle to only clean barrel groups or cold fouled barrel groups as the first shot needs to be zeroed if you know what I mean!

JD

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JDNC posted this 27 October 2007

Ric,

I've been shooting recently at 70 to 85 degrees F.  I don't know why I noticed this difference in pressure traces It just happened to jump out at me the other night while reviewing some of my trace files.  I usually get 1st and 2nd shot flyer's two or more inches from my main group from a clean cold barrel but only a inch or less out of a fouled cold barrel.  This barrel will produce sub moa groups after the first shot at 2450 fps most of the time.  If I could only get the cold shot with the rest!

JD

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Ken Campbell Iowa posted this 27 October 2007

Hi. yeah, different lubes do different things.  A while back, I was tryiing one of the many variations of Lithium chassis grease ....   amazingly enuff, it worked not too bad when ” warmed up” ( we will calll it for now ) but would throw the first shot from a 30 minute shooting interval  ( while I changed loads etc. )   a whopping 15 or 20 moa out of the group ... ie,nearly off the paper ..

My current model of this phenomenum  is that it is not necessarily ” termperature” of the bore, but of ” condition” of the bore (g) ....  or, to put it another way, I ain

I took a few years flyer (g) into rimfire bench rest, mostly because I just didn<

.... and if you changed ammo ( brands, ie, different lubes ) ya gotta shoot a bunch of them to get the conditioning you need ... usually I cleaned the old stuff out and with luck only took a few shots to have the shots come back to ” zero".

I played with different schemes to work on this, I thought that the use of Moly coated rimfire ( actually moly bore conditioning, not so much for bullet lube ... ) helped a little, but different barrels do this  ” warm up ” thing differently.

If you play with moly lubes, let me know how it goes, but be aware of over-lubing with this stuff ....  it takes only a ” glistening” amount to do the trick, and the best scores seemed to me to come after dry patching out the bore ( I never had to totally clean the stuff out... maybe couldn't anyway (g) ...   and then run a patch with a very light coat of moly on it followed by another dry patch ... the idea is to have just a very very smidgeon of moly * in the bore of the rifle itself *, not to exactly lube the bullet.

or, another view, I was conditioning the bore, not lubing the bullet; after conditioning the bore, I found that I only needed more moly on every 3 or 4 bullets, and the just a glisten amount

just some trivia, ken campbell, delta

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Glenn R. Latham posted this 04 November 2007

JDNC,

Do you have any poly or PVC wads to try?  That velocity is in the area where I find wads to help with bore condition and accuracy.  Worth a try.

Glenn

 

 

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Ed Harris posted this 05 November 2007

First shot fliers and pressure excursions are completely normal for all of the reasons you mention. This is why they discard the first two foulers in pressure and accuracy tests at the ammunition factories.  I have found that you can “minimize, although not completely eliminate” these by properly conditioning the barrel prior to the first shot.

In .22 rimfires, revolvers, cowboy and cast bullet rifles used for low to moderate velocities (below 1800 fps) provided that the load does not lead and settles into a “steady-state” bore condition, do not clean when you are done shooting. Instead push a wet patch through the bore to keep the fouling soft, and push two dry patches through the bore and dry the chamber prior to shooting your first shot.

If you have cleaned thoroughly you will either need to refoul or pre-condition the bore with a lube coated patch, followed by a wet patch and two dry patches.

You neither want the bore clean and dry, nor dry and hard-packed with fouling. You want it lightly fouled and slightly slippery. You can overdo the slippery thing. Any Telfon containing cleaner, such as break free is fatal to first-shot point of impact. I prefer Ed's Red.

When the Marines tested this in M40 sniper rifles with M118 Special Ball they found moly coating the barrel worked best in dusty desert environents, and would enable first-round head shots (1/2 mil extreme spread for ten first-shot-cold-bore repetitions) to 500 meters.  Whereas Mil-63460C (Break Free) left in the bore could not guarantee this any farther than 100 meters and sometimes had difficulty doing that.

If dust was not a factor “military cannon more cleaner” was said to work well, if you happen to have any.

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

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billwnr posted this 05 November 2007

When I shoot in CBA BR matches I usually shoot the first shot in the berm, the 2nd and 3rd on the sighter target and from there on the score targets. In the military matches I usually shoot the first 5 or so either into the berm or the sighter target until the gun settles down...then go to the score targets.

All guns are different and not all settle down quickly.

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CB posted this 05 November 2007

First off, please take that apostrophe away.

Now, maybe they're not first shot fliers. Maybe you guys are thinking about this backward. In the book I describe how to find first-shot-hit accuracy. In many cases the shooter is not interested in group shooting. The egg shooter or the sniper or the ASSRA stich target or one-shot target shooters must make that first shot count.

Hunters and these others need to know about the groups shot with first shots. My experience is limited with cast bullets and first shot groups,  but I've found that first shots do group. They ain't random.

Ascribing what may be mythical causes for the first shot effect isn't of much use, although it does allow a lot of technical-looking posting and agreement.

What kind of first-shot-groups do you guys get?

Where, may I ask, is the beef?

joe b.

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billwnr posted this 05 November 2007

My opinion is that anyone wanting a first shot hit should start with a fouled barrel. This is what I do when I'm hunting. Don't clean the rifle at the end of the sight in session and go hunting with a fouled barrel. Works for me.

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Glenn R. Latham posted this 05 November 2007

billwnr wrote: My opinion is that anyone wanting a first shot hit should start with a fouled barrel. This is what I do when I'm hunting. Don't clean the rifle at the end of the sight in session and go hunting with a fouled barrel. Works for me.

Bill,

I do the same, seems to work best.  Even with (ugh) jacketed bullets.

Glenn

 

 

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DonH posted this 06 November 2007

Joe Brennan wrote: What kind of first-shot-groups do you guys get?

joe b.

I don't know what a “first shot group” would look like from my Shiloh .40-65 (for example) but it ain't going to be in the same place as as a group resulting from subsequent shots. That rifle will always put the first shot from a cold clean barrel several inches above shots fired after that. I have never seen it to fail to do this though when shooting BP, use of a blow tube prior to shooting a first shot through a cold FOULED bore will result in that shot landing closer to the subsequent shots.

This may not prove anything either but is is a fact for that rifle.

 

Don 

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CB posted this 06 November 2007

DonH wrote: Joe Brennan wrote: What kind of first-shot-groups do you guys get?

joe b.

I don't know what a “first shot group” would look like from my Shiloh .40-65 (for example) but it ain't going to be in the same place as as a group resulting from subsequent shots. That rifle will always put the first shot from a cold clean barrel several inches above shots fired after that. I have never seen it to fail to do this though when shooting BP, use of a blow tube prior to shooting a first shot through a cold FOULED bore will result in that shot landing closer to the subsequent shots.

This may not prove anything either but is is a fact for that rifle.

 

Don 

I suppose that there are various bore conditions for the first-shot-group accuracy test. One is clean and oiled, another is clean and oiled then wiped dry, or dirty from the last adventure, or dirty from the last adventure, oiled and wiped dry before that first shot. It is interesting to read opinions on which conditions yield best accuracy, there are certainly a lot of opinions here!

joe b. 

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30-30 Wesson posted this 06 November 2007

JDNC, Hi.

You say that you get the first shot from the cold barrel 1” or less out of the, less than MOA group, and you want to use this rifle for hunting and you “want it zeroed, you know” My question is ” What are you hunting?” Mice at 200 yds? ;) Where a 1/2” deviation would mean a clean miss. If it's Deer then how will the  Deer know the difference and I hope you are not going to use your 30bhn, non-expanding bullets on game, what happened to ethical hunting? Are you going to have your bench rest out in the bush? Even with a Bi-Pod you will get heart and breathing movement.

 

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Ken Campbell Iowa posted this 06 November 2007

1st-shot-groups ... with 22 rf match rifle.

There was a tendency for the first ” warm up ” shots to make a group, usually always either  high left or high right, maybe 1 inch @  50 YDS ) from the ” warmed up and conditioned, score zero ” group.  In 6 years or so of shooting more ammo than I could neither find nor afford (g) ... I do not remember any rifle starting the 1st shot group low ...  but rarely a group would start at the score zero ... but then go into the warm up group, and either walk back to the score zero, or just go back and forth entirely, one or the other ...

this is interesting, but my only possible conclusion at the moment is that these shots were of higher pressure, so actually went faster and shot * 1 inch * !!!!!! higher at 50 yards ... wow, wouldn

I could come up with something if they were both high and low from the final stabilized zero .... such as ” the 1st shots because of throat resistance were victims of different ignition, and thus * out of tune *  ( because tuners can make the zero move around, higher and lower ) .... but as above, my first cold shots were always high.   geeeeez ...

1) is everyone elses first shots always high?  That would be very interesting ...

2)   when getting a FirstShotGroup, are you indexing your bullets?  ( in .22LR I was not indexing, so even more curious ... ) ..

DANGIT ... now I knew more before you brought up this first shot group thing....

Hey Joe, don

regards, ken campbell, deltawerkes

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30-30 Wesson posted this 06 November 2007

Ken,Hi. The only rifle I have that consistently throws the first shot high is my BRNO/CZ 22lr. This is out of a cold fouled barrel,as I very rarely clean the bore, only when the accuracy drops off. It is scope sighted,4x Pecar. I have not noticed my .303, .32-20,or my new .30-25-150 doing this, they are fitted with hunting type peep sights. I clean these with Ed's Red excellent bore cleaner. I zero my 6.5x55, jacketed bullet shooter, from a clean cold barrel, as that is the most important shot at game. The C.B. rifles certainly shoot to minute of Pig-Fox-Goat-Deer (from clean or fouled barrel ) so I wouldn't be afraid of taknig a shot at them from a clean cold barrel. Firing a fouling shot at the ground then trying to bag that deer/goat/pig would be counter productive. No matter what I read or hear about I just can't leave my rifle uncleaned overnight, let alone for the entire hunt,as some authors advocate.

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Glenn R. Latham posted this 07 November 2007

Hi Ken,

I haven't wrung out .22 rimfires for flyers, so can't comment on them.  My most recent testing of clean bore POI showed the first two or three shots landing outside the resulting group to the right.  This was in the .30-06, cleaned with Shooter's Choice, and bullets lubed with three different lubes (LBT, Alox/beeswax, and M&N).  Here is a typical group:

 Well, hopefully it attached!

Glenn

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Molly posted this 12 November 2007

Interesting thread, and I wish I could contribute something more substantial to it, but FWIW, I've found that the dried residue of Hoppes #9 is a serious offender in this regard. I've quit using it entirely, and just use a very dilute solution of Alox 350 on a mop to preserve the bore of my rifles. I also tend to run a patch wet with lighter fluid up and down a cold bore before shooting. Follow with a dry patch, and any question of residual lube is eliminated. Someone might want to try this for every shot vs 'normal' shooting to see if it makes a difference.

FWIW, most of our lubes fall into the class of crystalline polymeric materials like waxes. I haven't tried to test it, but it's entirely possible for a lube to crystalize as the barrel cools. The crystals may not be extra hard, but I'd expect them to be harder than the same lube before cooling. So the train of thought may have some merit, but is a long way from proven.

I concur that the first shot is likely to be a bit high. Why? I dunno.

HTH Molly

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JDNC posted this 13 November 2007

30-30 Wesson,

As to your first question, I thought this forum was about cb accuracy and learning and sharing new information about cb shooting.  As ethical hunting goes, I was entertaining the thought of using a 30 cal this year (LBT LFN with 30bhn base and lead soft-point) but I changed my mind and decided to use my 45/70 with 400 gr. WW (12 bhn)  paper patch at 2150 fps.  I took a buck yesterday and as usual with this load it fell where it was shot!

Hope you feel better,  I know I do.

JD

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30-30 Wesson posted this 13 November 2007

JD, G'day. Good for you on the Buck. I do feel better. Use enough gun, that's the way. This forum IS about sharing infomation, my accuracy aspirations must not be as high as other shooters are.

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