Can't help with the .45-70.
A friend leverlotioned a deer with my Remington .30-30 after her .270 was stolen.
I can't say it was any deader than a Corelokt would have killed it, but the trajectory is a bit flatter. Not that the critter was shot at any great range.
Handloaders hate them because the brass is shorter than standard to get the rubbernose hemi semi demi spitzer within OAL specs.
I have a few facts and a lot of opinions.