What about the 450 Alaskan looking at ballistics the 350 does 2415 with 67.0 of IMR3031 and with 66.0 of IMR4064 it shows the 500 at 2005 FPS. Whats the top velocity in the 45/70 with a 350 grain bullet ? I myself load 45.0 and 47.0 of IMR4198 for 1900 and 2000 in a 22". And i once chronyed the 350 Hornady RN out of a Marlin 1895SS 22" at 2130 and i beleive that was 50.0 of IMR4198, but i now never go past 47.0 of IMR4198