Baikal indicates their double rifles are safe for 32,000psi. - or CUP, max pressures IIRC.

At this pressure level, I think most guys would agree the recoil was all that was desired.

As for powders, Varget and H4895 will allow full density loading with some compression in the standard .45/70 case with bullets crimped. The pressure generated would be under the rifle's max. listed and speeds just under or at 1,900fps with 400gr. bullets, a few more gr. for 2,000fps with 350's, using either of those powders.

For pigs, elk, moose and deer, I'd probably use the 405gr. Remington FN, or could use the Speer or Barnes OldStyle 400FP - just don't shoot them through the front shoulders - shoot them through the 'lights'(lungs).

The 350gr. Speer might need a longer throat, or 2" case to allow seating and crimping. It is the 'tough' bullet of he .457/8's for the .45/70. Some guys really like the 300gr. Nosler Partition which actually gives terrific penetration, I've read. The 350gr. Speer needs to start as fast as possible - over 1,900fps at least. You can do this in this rifle.

Crimping is good (almost necessary) in this round, as it aides in powder burning. Straight cases should be crimped or ignition problems can surface as well as producing large pressure changes resulting in large shot to shot velocity variations.

If mine, I would also throat the chamber for a longer seating depth - probably 3/8" 'leade' or 'freebore' would be good if you wanted to shoot 350gr. or heavier bullets.

A 3/8" freebore or leade is what I had put in my .458 2" chambering reamer.

A 3/8" freebore or leade in a .45/70's 2.1" chamber, would give the same O.A. Loaded length as a standard Winchester 2.4" chamber would provide ie: the same as the .45/90 designed for short, light bullets from 290 to 300gr., as it was originally chambered by Winchester.

There are many other suitable powders for these rifles, any rifles chambered for the .45/70, of course. Simply pick up a Hodgdon's Annual Manual (every year) and see for yourself.

Richard Lee's handloading manuals 1st and second edition also have good data for this and other rounds.

The 2.4" Sharps (which Oliver Winchester copied for his M86 lever and model 85 SS) on the other hand, used paper patched bullets which were tapered allowed long seating, increasing the useable capacity thus the use of more powder with heavier bullets, ie: 90 and 100gr. with bullets to 540gr., I think -- 500gr. anyway in factory loaded fodder.