50 grns of 4198 seems like overkill to me! If that what you want to do though, go for it! I have been using 35 grn of IMR4198 behind a 405grn remington soft point. I killed a 200+ lb black bear with this load this spring, full pass through, and I just killed a whitetail doe with the same load yesterday. Full pass through both shoulders at 75 yards. I just don't see any need for that added velocity in a 45-70. If I wanted a round over 2000fps I would shoot my .308, or 300 win mag. But, as I said before, if you want it going that fast, and you don't mind the recoil, go for it!
