Poor accuracy in 03a1 sporter

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  • Last Post 16 May 2013
Ben Cartwright SASS posted this 24 April 2013

My 03a1 sporter slugs at .308. I bought from bullets from a dealer (150 gr RNFP) and when I tried them I couldn't hit the backstop at 100 yards, at 50 yards I couldn't hit the paper and at 25 yards I was getting a 5 inch group off a rest. I tried some other cast bullets I bought from Moyers bullets last year, 150 gr from a RCBS 30-150-SP and they shot nice a sub 1 inch group at 25 and 1 inch more or less at 50 yards and 2 at 100. Both batches are sized at .309 and it turns out both are in the 20-22 BHN range. But one shoots great and one doesn't, both are loaded with 15 grains of trail boss and WLR primers and commercial brass. The only thing I can see is that the one that shoots well has a slightly smaller flat point and a more tapered round nose.

I tried a batch of 180's from the 1st dealer and they also shot with poor groups. I have some 173 grain bullets from my Lyman 311041 mold and they are closer in group size to the Moyers bullets, although not at tight and they are straight wheelweights.

I am stumped. Could the bullet silhouette make that much of a difference or is it something else?

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Chargar posted this 24 April 2013

A couple of questions;

Were the bullets that shot poorly plain base or gas checked.

Were the bullets that shot well plain base or gas checked.

If there are different answers to the above, there you will find your answer.

If the answers to the above are the same, the obvious answer is bullet vendor #1 is making and selling crappy bullets. Could be the alloy or could be the lube, or could be both.

Bullet shape might make some difference as well as bullet fit, but that won't explain the mammoth difference in performance you have experienced. Small meplat vs. flat nose won't make that much difference.

Of course always check for loose action screws, sight screws or scope mount screws. Over the years I have known of many rifle whose accuracy has gone south that could be traced to a loose screw or two.

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Ed Harris posted this 24 April 2013

Bullets should be throat size, not groove diameter.

I expect if you cast your Springfield chamber the ball seat ahead of the case mouth on a new barrel is probably .3095-.310.

If the bullets you are shooting are plainbased, without a GC, the commercially cast bullets are typically too hard. With plainbased bullets you are better off with alloys not harder than wheelweights.

Also important is that the diameter of the forepart of the bullet be large enough to offer resistance to the rifling.

I expect that if you took the bullets which shoot well and poke one nose-first into the muzzle you will have firm resistance as you push it in and the bore-riding portion will show at least some light engraving.

If you take the bullets which don't` shoot and poke one into the muzzle nose first, I'm willing to bet they just fall in all the way up to the driving bands with no resistance and no marking by the rifling.

Therein lies a clue!

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

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RicinYakima posted this 24 April 2013

There is a ton of '03 data in the Military Rifle data cards from the National Matches. Go to the CBA “home” page and scroll down the left side of the page. HTH, Ric

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Ken Campbell Iowa posted this 25 April 2013

also ... don't trust written specs ... measure everything yourself ... then write everything into a ” log book ” ( now a computer database ... of course ( g ) ) ..

... and i always think of buying commercial cast bullets about the same as going on a blind date ... ( g ) ..

ken

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Michael K posted this 25 April 2013

Ditto on the blind date. Granted it's not an '06, several years ago I purchased 500 .258 86gr FNs from a well known commerical bullet company in a PB copy of the 257412 to run through a 25-20. At that time my time was worth more than the day I would spend casting. Did not shoot worth a hoot yet they miked .258 dia. Even at 25yds they were completely worthless. Tried 4 different powders with vels between 1000-1400. Thinking something was amiss I assembled some control loads I used with the 257420 and 257412 both sized .258, along with the above FNPB commerical bullet. Same result, except the 2 Lyman bullets shot just as expected and the FNPB shot like c--p. I also tried a few of the FNPB loads with the Lyman bullets, eveything went well.

Sorry your date did not go well. Don't feel bad, somethings are just not meant to be. I am sure you will find another that will be a better match. They may be nice bullets, and blind dates may be nice girls (buck teeth and a perfect 38 (38-38-38) comes to mind)

All the best, Michael

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Ben Cartwright SASS posted this 25 April 2013

Normally this wouldn't be a problem both guns love the RCBS 30-150-SP bullets that Penn makes and I would order more from him, but he is not making rifle bullets until he catches up on handgun bullets, figures it may be a few months, so suddenly I am trying to find another bullet that my Postal Match gun likes, as I am down to my last 20 bullets from Penn. I bought a micrometer and the two bullets that shot lousy mic the same as the good bullet. The bullet that shot poorly (I will call it FP for flat point) is not gas checked and has a slightly rounder profile in the nose and a larger flat area, the SP is a semi-point. I loaded them the same, 15 grains of Trail Boss, previously I had tried the FP with 5744 and it was even worse (pushed it at about 1850)

I checked the bullets in the muzzle and the SP (good) went in right to the crimp ring, while the FP (poor) engaged the rifling sooner with about a 1/16th sticking out, the .311 bullet also engaged the rifling sooner (it shot not much worse than the SP but it is straight WW and therefore softer than the FP which is a 20-22 BHN, could the FP be too hard to really engage the rifling or something? A friend gave me 20 bullets from a Saeco mold that mic less than .309 and go in right to the driving band and I will try them this weekend.

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99 Strajght posted this 25 April 2013

For bullets in the 30-06 with out gas checks to shoot well,  I have found that they have to be softer. About 12 BHN. Larger, about .311. And slower about 1300 FPS. With the bullets you have try slower. Glenn

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Ben Cartwright SASS posted this 25 April 2013

I have a bunch of the 311041's that are sized to .311 that don't have checks yet and will try those, they are straight W/W's and at most 12 and with TB they will fly about 1150-1200.

Boy there is a lot to this cast bullet shooting! I had figured it was just cast them up and shoot them, like factory ammo or my Cowboy handguns that eat anything. Of course there I am only hitting a 8 inch target at 15 feet to ping it.

This is actually fun, trying to figure it all out, only wish I didn't have to work and could spend all my time playing with this.

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Chargar posted this 25 April 2013

Plain base rifle cast bullet can and do shoot well, but are entirely different animals from gas checked bullets. They can't be treated as the same in regards to alloy, power pressure/velocity and size. As stated, herein is the answer to your question.

I long ago gave up on buying cast rifle bullets and I never found one that could give me performance anywhere near what I could cast myself. Most often (not always)commercial cast rifle bullets are produced with an eye on the bottom line. So, many important performance considerations get lost in the profit margin.

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Ben Cartwright SASS posted this 25 April 2013

Doesn't make sense the shortest bullets with the longest jump, seated with maybe 3/8 inch showing, are the most accurate. I tried to find the OAL by chambering a round only partly seated, my way of sizing and trimming a case and starting a bullet it in didn't work, my longest bullet, a Saeco a good 1 1/4 inches long didn't get pushed into the case at all stays where I set it at between the gas check and the first lube groove and no rifling marks. In any event the bullets that are the most accurate the RCBS SP's are only showing 3/8 of an inch beyond the end of the case so they would have quite a jump to the rifling but I am getting 1 inch at 50 yards. Doesn't make sense

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Chargar posted this 25 April 2013

Ben...Cast bullets use a different rulebook than jacketed bullets. That said, many things about cast bullet shooting often seem counter intuitive.

The Krag rifle has a very very long throat and bullet seated out to the lands produce rounds that are way to long run through the magazine. But Krags still manage to do well in spite of the impediment. Other military rifles are in the same boat.

A bullet seated far enough out so it doesn't hit the rifling on a run is the best possible situation, but not have that is not always the kiss of death (accuracy wise) either.

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Ben Cartwright SASS posted this 13 May 2013

a couple questions, they may sound dumb or redundant but bear with me.

I bought 3 more batches of bullets, 100 each, I am trying to find what bullets the gun likes before I buy the mold. The new ones are all Lyman, but I don't know the BHN, am trying to find my Lee tester to check. The styles are .311291 .311407 .311440 I went to the range and shot at 50 yards off a rest, got 2 1/4 from the .311291, 4 1/4 from .311407 and 3 3/8s from .311440, they were all 15 grains of Trail Boss. I then shot the RCBS 30-150SP the gun seems to like and got 1 1/4 (5 shots in 2 minutes). I will try some more testing with the .311291 and see if I can tighten that up.

The question I have is back to the Penn Bullets discussed above, They are 4-5 inch plus groups at 50 yards, while I feel that it would be wasting time to try to get them to shoot tight, I have 500 of them, should I just melt them or use them to practice trigger control and sight picture. With the Lyman .311041 and the .311291 giving better groups (the SP is the best and am looking for a mold) I am wondering what to do.

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CB posted this 13 May 2013

You certainly are having a hard time. In my opinion;

1 You are wasting your time buying cast bullets to decide which mold design to buy. More than likely the mold you buy will not have the same dimensions as the bullets you bought, every mold and every alloy will cast a little different in dimension, .0005” in diameter on the nose can make a difference for bench rest accurcy. You need your own casting alloy of at least a 100lb. batch and you're own molds to try.

2 Like Ric said, look at the CBA website at the match results. The top four powders used are not by chance; Alliant 2400, SR4759, 4198, and 5744. I'm sure the winning shooters using these powders are winning because of exhaustive testing and experimenting to gain a winning accurate load, NOT because somebody told them to on a shooting forum. The CBA bench rest program is the only one of its kind and that is why a brief loading data of each shooter is shared to help other shooters. I personally tried Trail Boss in my known accurate load bullet/powder combination in my 03-A3 rifle and it failed badly, no matter what I tried. Oh, it did go boom and it did put the bullet on paper, but nothing as far as bench rest accuracy at 100yds.

3 I would guess that your 150gr sp load is the most accurate over the others is by happen-chance, not by any extensive development you've done. I think if you want the shortest one-mold route would be to contact LBT moulds, Veral Smith. Buy his slugging kit, follow HIS directions, mail the slug back to him and he'll make a mold to cast a cb to fit your throat. Throat fit is the most critical, not bullet design. If you want a plain-base bullet in 150-160gr range, I think that would be the best way to go with LBT. We have a successful shooter in our club that shoots a Swiss rifle with a Lee mold (I think 170gr) with no gas check using Lee tumble lube and 9grs of Unique. It is a very competitive load.

It would be a lot easier learning curve for you if you could speak first-hand with other CBA shooters so they could show you what we are trying to explain here. Shooters that have showed me were winning shooters and had 15-20 years experience, which made all the difference to me when I started BR competition. It will take time for you and anyone new to gaining bench rest accuracy in their endevours. It isn't just a do-this do-that and your set to go. Keep records and learn from you own experiences and enjoy the time shooting, developing and testing.............Dan

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buffalo george posted this 13 May 2013

This reply should be carved in stone.

The most cheap way to start bench rest shooting is to pay the cost of a costly custom mold made by Veral Smith of LBT, I prefer the 4 cavity gang molds.

Buying commercial bullets or using non custom moulds might be sufficient to plink from the standing position.

Hoping to find bench rest accuracy in roll of the mill moulds is like buying a ticket at a lottery.

 

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onondaga posted this 14 May 2013

Dan and George are spot on.

My 1903A3 shoots great. I have honed my molds and bullet sizing dies so that when I hand chamber a round I can feel the bullet slide in the throat and the round cannot be seated by hand because the length overall includes .010” engagement of the bullet by the lands. My loads can only be seated with the bolt.

This kind of fit is not by happenstance, commercial bullets or from somebody else's load book. it takes real work. My molds are the Lee 170 and the 185 gr shot barely  just over  2,000 fps with H4831SC or H4895 for a deer hunting load level.

If you can learn chamber casting, that can shorten the process and now RotoMetals offers an inexpensive and terrific chamber casting alloy:

http://www.rotometals.com/product-p/chamber_casting_alloy.htm>http://www.rotometals.com/product-p/chambercastingalloy.htm

http://s30.photobucket.com/user/rhymeswithwhat/media/03sight2.jpg.html>

Gary

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delmarskid1 posted this 16 May 2013

I would shoot the store bought cast bullets with a light pistol powder charge. They will make for great off hand practice. My Springfield shoots well with factory molds. It shoots BETTER with carefully fitted cast bullets than with stuff that I make a bunch of to hear the gun go off. I like to do both.

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Ken Campbell Iowa posted this 16 May 2013

ben sez:: I have 500 of them, should I just melt them or use them to practice trigger control and sight picture. With the Lyman .311041 and the .311291 giving better groups (the SP is the best and am looking for a mold) I am wondering what to do.

ken sez::

i would be interested in the ~500?...bad ... bullets ...i think i have a rcbs 150 gr mold blocks ... i would trade you ...if interested, i will try to dig it out to be sure ... post me my pm no workee

ken

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