The .577/450 loaded with black powder, was about 100fps faster than the black powder loaded .45/70 when used with the same weight bullet. Smokless powder does change that, somewhat.
; I can see where people who aren't handloaders might look at WW or RP factory .45/70 ammo and sneer at the .45/70's ballistics. I understand there would be confusion in this case. Afterall, how can anyone take 1,320fps with a 405gr. bullet seriously, for anything that might bite back?
; Considering the same weight bullet with modern designed jackets and cores, driven at 2,100fps changes things a bit.
; The BP rounds ran around 20,000PSI, whereas these modern rifles can handle up to 43,000PSI. This changes things a bit.