Why anyone loads a 45-70 past the 1870's standard load with a 405 grain bullet at 1350 FPS is beyound me. There isn't an animal in North America that could stop one of those bullets at that speed...
WHY???? Because you can...
I do believe that this one would have worked well too!!!
Bottom 'mushroom' 500 grns trundling along at about 1250fps.. top 450grns.... Paper Patched of course.... recovered from a damp sand berm.
I have shot them at 1600fps mol, recoil was...um...er...stout????