Has anyone taken the .45-70 or the .450 marlin and necked it down to .429. Dont know if there would be much of a gain but the increased powder space should alow you to pump up velocities above what a .444 could do with lower pressures. It would be relativly easy to do. I know that any of the above cartridges will have more power then I will ever need but I just like the bottle neck cartridge more and like the idea of creating a cartridge that not everyone has.

Why not blow the 45-70 out straight wall and neck it back from .475 to .458? You then have your bottleneck case and the same bullets and barrel will work.

45-70 improved ?

would there be more of a chance of feeding problems with a straight walled case vs. a tapered case

I would guess there might be, but the .480 ruger works in a lever gun so maybe there wouldn't be a problem. The .480, being based on the .475 Linebaugh, is based on a straight walled 45-70 casing...but much shorter.

I suggest you read up on the .38-56 cartridge; it might provide ballistic insight to wildcatting the 45-70 in the manner you speak of.

My problem with the older cartridge is the fact that any published data would be to a very low psi rating for the old guns. I know that I would not have any published data with a wildcat but there would be no chance of someone loading a high psi round into an old gun that cant handle it. Probably a one and a million chance but enough of a reason to say I want something even more unique. I started out looking for something like the .416 beartooth but I guess that kind of died then I thought of how easy it would be to buy a .444 barrel and ream it out and put it on an 1895 action and that would be it. The .416 would require a custom barrel made.

So what is your reasoning for the mod? Granted, I haven't been bitten by the urge to "Wildcat"; but in my readings of P.O. Ackley, Watts, and Gibbs - generally speaking, wildcatters try to improve on some quality not offered elsewhere. Bigger, faster, better and so on. It sounds like you just want something that no one else has...which is fine, but are you trying to solve a perceived problem?

Just Curious,
Texican

Cum catapultae proscriptae erunt tum soli proscripti catapultas habebunt

There really isnt a point to it, just trying to see what kind of velocity increase could be gained by it. It was more of just a thought that just got in my head. I would really like something in the 375 - 416 range that would be on the 1895 frame. Just cause. With a 375 I really think faster loads could be created with a larger case capacity then the 375 winchester was able to achieve as a straight walled case.

I just now am looking at a 45 colt compared to a 44 mag case and realize there isnt much of a difference.

For now I will just keep playing with my .35 rem 336.

I'm not sure you'd really gain that much. Even the 416 Barnes (45-70 necked to .416) only pushed a 400 grain bullet about 1900 fps or so, IIRC due to pressure limitations. I think there was more backthrust with the necked down cases which came into play. Of course the BC/SD of the bullet would be significantly better than the standard .458 45-70 or .429 444, but not enough to make it work the trouble. Any necked down cartridge should show more backthrust which forces lower pressure to offset.

You do have my interest stirred up once more. I may have to explore that project again.

I know that the .416 barnes was created a long time ago but I dont know what pressure it was loaded to. One of the big things I look at in my reloading manual is the .348 winchester. I know that it is longer and has a huge amount of powder capacity, (4.32cc), Now it can take a 220 gr. bullet and throw it at about 2400fps and only run 25000-30000 psi. Compare this to the 35 Remington that has 2.85cc capacity. Max loads for the 220 gr. bullet run about 2000fps but this is already at about 32160 psi. Now is all of the pressure difference just from the case design of the 348 or the massive amount of capacity.

What I have been trying to figure out is could just increasing case capacity allow you to :run lower pressures at the same speed or higher velocities at the same pressure as the same bullet diamiter with less case capacity.

Another cartridge conversion I have been looking at has been the .357mag to .357 Bain and Davis.

All the numbers are from the "Modern Reloading" second edition by Richard Lee

[QUOTE=Jayhawker] Any necked down cartridge should show more backthrust which forces lower pressure to offset.


Bottlenecked cases do not increase bolt thrust. Two cartridges with the same cartridge heads loaded to the same pressure have the same bolt thrust regardless of bullet caliber.

I would think that the 405 Win already plays pretty well in the range that you're targetting... though I don't think that there is nearly the same variety in quality bullets for that cartridge (yet). I'd like to see
Marlin make a rifle in this caliber - might not be as pretty as some Winnies, but it would be affordable by the masses !