because there is no shoulder on the .45-70 cartridge i think the slower powders are more problematic. i wouldn't pick one that slow; and i'd use magnum primers with anything as slow as imr-4350 or a case-filling load of h-4831. that would also require a heavy bullet and a heavy crimp in my opinion.
i've suggested the use of imr or h-4831 before in the .45-70 to reduce recoil and to achieve high loading density. but the conditions noted above are the way to go with it.
no, i don't shoot a .45-70 and haven't loaded for one. that doesn't mean i don't understand how it works.
take care,
ss'
