Daryl.

The 45-70 rears up a bit with 2100fps loads, your laods would certainly make it sit up and bark. I am getting excellent accuracy with Wougliegh 350 grn projectiles at 2250 fps and ADI 2207. I slightly favour the 45-70 over the 450-400, but either will do the job. Longer barrels would help balance them a bit I think.

Wayne