I use a 375 HH with 300gr bullets, but I know someone in Eversham, uses a 45-70 on everything and reloads, I'll ask him if I can pass his details on.
For my marlin 45/70 I use 30 grain reloader 7 and a 405 reming ton soft point , very good accuarcy on paper, not used in anger yet, but hope to blood it on the does next month
RL-7, 3031, H4895 would be good powders for that length of barrel. I would use the 300 grain bullet, mostly due to the bullet shape which will feed well under less than perfect circumstances. I use a similar RCBS 45-300GC in my Mauser 98 45-70 and a Marlin 1895. For a 45-70 is shoots flat, and hits amply hard. I hit a large mule-deer doe with that bullet at 70 yards (over RL-7) and it was like the Hand of God. Down instantly without even a quiver.~Muir
Thanks guys, looks like RL7 or H4895 is the way to go then. What do you think about H4198? Seems to crop up quite a bit googling around and is a bit faster than 4895 (thinking of the short barrel)?
e.g. 350gr Honady 45-70 load - HuntingNet.com Forums
Another good powder. I just shoot a lot of 4895 in other calibers so I lean that way. One of my most accurate loads was a stout charge of RL-7 under a Lyman 457-122 HP. It would shoot clover leaf groups at 100M. I ran out of RL-7 and used some of my vast supplies of 4895. It shot about the same so there I stayed. I use 4198 primarily for light cast bullet loads for bottle necked rifle cartridges.~Muir
Do not forget to crimp the rounds before you use them in the underlever as the bullets will move back in to the case with the recoil! but i guess you knew that.
"a man does good business when he rids himself of a turd"
I never hesitate to mention that if you are using a 45-70 you should make every attempt to cast some of your own bullets. I can't imagine what those commercially cast bullets are running you but I can guarantee you can make them for pennies. Some of the best designs just aren't commercially available. The ancient 330 grain, Gould Hollow Point bullet, Lyman #457122 is an example. They are tedious to make but oh so accurate and a ferocious killer of game. Between that and the RCBS bullet mentioned earlier you have my favorite and most often used 45-70 bullets in my bolt gun. My son favors the HP in his Marlin.~Muir