Lymans #457122 accuracy issues

[mikeg1005]

We own a Uberti 1876 centennial.. specs on the gun are
45/75WCF
28" barrel
.458" dia. bore

Since factory ammo is about $4 a shot we cast/reload our own.

We have been using this mold...

http://www.buffaloarms.com/browse.cfm/4,1537.html

With a 42 or 43gr charge of H4895 behind it, OAL just at the beginning of the rounding off at the top...so it gives an OAL of I think 2.25" (I don't recall for sure the number but its around there.... on my chrono it gives me a 1525fps average...

We cast 50/50 (linotype/pure lead) BHN of around 15ish... and lube/sized to .458" dia.

I have faith in myself being a good shot... the gun has iron sights that aren't anything to brag about but I can still shoot with them... so I rule shooter error out.. the accuracy at 100yds is really nothing to brag about... probably 6" at best, from a rest....and going out to 200ish yds its almost a 1' group if you can even pull it off.

I understand that people load this same bullet in 45/70... is this bullet just not accurate or am I getting decent groups for the gun I am shooting?

Any help would be great because its a fun gun to shoot but accuracy isn't really what I'd like it to be.

MIke.

[btroj]

That bullet is capable of better accuracy than that. At least at 100 yards. 200 with irons is not easy. This is the type of thing that separates the men from the boys. Stick with 50 and 100 yards and see what it does there. Face it, this is not mos peoples idea of a 200 yard rifle anyway.
You might they a different size to diameter. Try .459 or ever .460.
You also need to try different loads with that powder. Chances of trying one load combination and having success right off is small.

[Bass Ackward]

Huge subject for your first post. And quite honestly, you are going to get a myriad of recommendations that you may or may not be prepared to deal with. I tell you this so that you can learn how to help yourself on other subjects as well.

Use the search button at the top and search for threads involving throat slugging, bullet fit and sizing, rifle lubes, plain base velocity limits, and 45-70.

This will give you many hours of research that will get you to understand more of how broad the subject is that you are asking.

Welcome to the board.

[45 2.1]

You have several options:
1. Go with the original alloy loaded in the period cartridges when it was new. That would be a lead/tin mixture somewhere around 20:1 to 30:1. Softer is sometimes better. Just lube your boolits without sizing and see if they will enter a fired case neck with no crimp left on it. If they do, shoot them and see.
2. Paper patch some to throat diameter.... cast those very soft and size them down to 0.452" to 0.454" and patch back up.
3. Try some light jacketed bullets to see if the gun is the problem.
4. Softer alloys work better in the 45 caliber rifles.

[mikeg1005]

Yes big first post indeed...

Thanks for the info, I will search for it... I've always liked this site... used it quite a few times to look up casting stuff so I figured I'd become a member and ask questions, very friendly group of shooters on here.

I have read a few posts that this projectile mold is actually "not accurate" compared to others due to the HP design.... I have a feeling this is a false statement though.

MIke.

[MtGun44]

HP is much more often seen as an IMPROVEMENT in accuracy, not a loss.

What is your barrel groove diameter? THE most important first thing is to study
slugging and fit. Short version is that you will likely need to use a boolit .001 to .003"
larger than groove diameter, although this does not stand alone in this issue, but it
is an excellent place to start. As Bass and 45 2.1 said, study will be required and softer
is likely to be better.

Each gun is a thing unto itself, but there are signposts, best practices and 'high
probability of success' routes blazed by those that went ahead of us.

A final note - I have personally never gotten any good accy with that boolit, but
I have only tried it a couple of times and not had any chance to sit down and do the serious
job that it is appaently going to take in my particular .45 -70s.

I have had very good results with RCBS's excellent 405 GC boolit at 1750 FPS from
a Marlin Guide Gun. That is part of the reason that I haven't gotten back to the 457122,
but it is on most people's "known good design" list.

Bill

[btroj]

Use the search feature here. Also read up anywhere you can to see what others have done.

In the end however, don't be afraid to learn on your own. School of hard knocks can be tough on you but it sure feels good once you figure something out.

You will get enough advice here to keep you busy experimenting for a while. Enjoy it, this is what makes boolits so fun.

Goood luck and let us know what you discover.

[76 WARLOCK]

I use that bullet in my 1895CB and get 1"-1.5" at 100 but I use a much softer mix, if I use a ww alloy and get leading.

[Larry Gibson]

Ignition inconsistencies can cause problems with that light of a bullet in the larger 45-70 case with its large expansion ratio. Drop back to 36 gr and use a 1 gr dacron filler. Work up from there in 1 gr increments until accuracy goes south again. Also 1500 -1600 fps is the borderline area for best accuracy using PB'd bullets, especially with the softer 15 bhn alloy.

You might consider a slightly faster burning powder like 2400, 4198, 4759 or 5744. I also use the dacron filler with those using bullets of 300 - 413 gr for best results.

Larry Gibson

[Mk42gunner]

Mike,

I would almost bet that it is a combination of things: Bullet fit, Alloy hardness, and Pressure/Velocity level.

How did your factory loads shoot? I am guessing they shot better; since you are asking questions. What was the muzzle Velocity?

Cartridges of the World, 11th Ed. gives a factory load 1383 fps with a 350 grain bullet. The only other load they give is 24 grains of IMR 4198 behind the Lyman 456192, a 350 gr bullet for 1380 fps.

I would say you are okay with the Gould bullet since it cycles in your gun. I don't think I would load much hotter than you are doing though; everything I can remember reading says the 76 Winchester is not a strong action.

Really silly question-- how does the hollow point look in your bullets? What I am trying to ask is if the bullets are well filled out and balanced. You may have to try a different alloy.

I have always liked the looks of the carbine version with the loong forearm myself.

Robert

[excess650]

Your 47-75 may have a slow twist barrel and be happier with a 300gr bullet.

[Trifocals]

re: the 457122 hp bullet, I received the following load from my good friend georgewxxx who posts on this forum. alloy=WW, size boolit for proper fit, 27gr 4759 (work powder charge up as you feel necessary). This load has given outstanding accuracy from any .45-70 rifle it has been tried in. LOL