Help me design a bullet for this rifle

[Doble Troble]

This is my "new" buffalo rifle in 38-55. The target shown (4" paper plate, the 6 mm hole was from my neighbor at the range sighting in his 243 ) was at 100 yds with the bullet shown a gas checked LLA lubed Lyman 375449 (I think). I cast them from mutt metal (a mix of pure lead and melted-down range finds) sized to ~ 376 with a Lee-style home-made sizer.

The rifle is a formerly abused and rusted 32 spl found cheap at a local pawn shop. I put one of the A&B F44 375 barrels that are on sale at Midway and chambered in 38-55. I've really lucked-out and it has shot some good groups and does really well with the gas checked bullet shown and 20.8 gr of 5744. I used it to shoot in our local buffalo shoot this weekend (I used to shoot a 30-30 which was problematic at 200 yds not in-terms of accuracy but in-terms of telling whether or not the bullet hit the target. Those 30 cal bullets just don't ring the gong). I shot 23/25 which is the best I've ever done.

The problem is that although the rules state that gas checks are allowed, it was clear that my use of them was frowned upon and appears "gamey". The challenge is to come up with a plain based bullet that will be as accurate and more in line with the spirit of the contest.

I've slugged the bore and the grooves are .376 and the lands .365. Edit due to bad measuring: the throat is 0.166, base to rifling = 2.295. The twist is 1/12 and so I'm thinking I want a long bullet about 330 gr, maybe between 1200 - 1400 fps?

Is there any more information I need to design a bullet for this rifle? I'm thinking about trying the on-line design at Mountain Molds.

[Bass Ackward]

I've slugged the bore and the grooves are .376 and the lands .365. There is 0.410 distance between case mouth and the begining of rifling. The twist is 1/12 and so I'm thinking I want a long bullet about 330 gr, maybe between 1200 - 1400 fps?

Is there any more information I need to design a bullet for this rifle? I'm thinking about trying the on-line design at Mountain Molds.

DT,

You may want to play around with cartridge OAL until you see what the maximum nose length for your bullet can be. This can alter olgive angles and more. I would forget weight for right now. Personally, I would reverse engineer the bullet by determining the nose length and shape criteria and then adding enough shank until you got the look the way you want. Then let the weight be what the weight works out to. As a last stage, you can play with band width etc to get a weight that is acceptable to you.

Play this game each week going strictly from memory until you get three bullet designs that are very close to the same. Then you should have something you will be satisfied with. Especially if it performs as you imagine.

[drinks]

DT;
Lee has a .375 at 250gr plain base mold, about $20 at most places, why not try it before you go the custom mold route?

[Buckshot]

............Mountain Moulds isn't accepting any new orders until he gets moved and setup again. COUple months, probably.

That 250gr Lee slug that was suggested is a good one:



It would be the one on the right. Left one is a 225gr Saeco. The Lee's from my mould drop at .380".

..................Buckshot

[Bass Ackward]

............Mountain Moulds isn't accepting any new orders until he gets moved and setup again. COUple months, probably.

..................Buckshot

Richard,

aaaaaa. I ordered one yesterday as he had 6 extra block sets I believe. First come, first served.

There is still one brass set of blocks left and that will be it until about August. So if you don't mind brass, (and I love it for handgun bullets) there she is. just post on his forum that you want it.

[Doble Troble]

Thanks for the good advice everyone. I started-out with the Lee 250 gr PB with marginal results which led me to the Lyman gas checked design.

Any advice about whether I should consider a bore rider vs non-bore rider?

[moodyholler]

I don't beleive 330's will function thru the action. 280's are marginal seated to the crinp groove in mine. I have some 350 grainers if you would like to try them but they are RN. moodyholler

[Bass Ackward]

Any advice about whether I should consider a bore rider vs non-bore rider?

DT,

Play the fit it up game and see if you have the option available. If you do, then a short section for alignment isn't going to hurt anything since your velocity expectations are fairly modest.

[Doble Troble]

Thanks again everyone. I see how this becomes an obsession.

I do think I'll have room for a riding section and have started preliminary investigations with Mountain Molds online software - which even if I can't get a mold from them any time soon has been very educational.

Thanks very much for the kind offer, MoodyHoller. I'm not worried about running them through the action because the way I have the forestock right now, its a single-shot. This may (and I think probably should) change in the future (I don't want John Browning spinning in the grave due to my lack of engineering skill). I don't want to put you out at this point, but maybe after I've exhausted other options I'll come begging back.