I do not own a 45/70 but if I ever found one with the right price I would buy it in a heart beat. they are one of the most versatile rounds I've ever seen. my brother in law has 2 of them and he tinkers with a number of loads.
his elk this year was shot with a 416 grain hard cast hollow point bullet, more than enough stopping power to drop a buffalo if needed. believe it or not, it doesn't kick all that bad out of a lever action but I wouldn't want to try those loads out of his contender.
he has rigged up a 'pop gun' casing that uses offset 22lr blanks as charge and you just pop a 45 cal round ball in the casing and let her rip, it sounds like a bb gun going off and it decapitates squirrels, great for vermin control especially if you have close neighbors
my favorite is his 'bucking ball' loads where he loads the powder, plugs it with a gas check, then follows with bird shot and caps it off with a round ball, he used the bucking ball to finish off his elk and it still easily penetrated the skull. I think those would be an amazing home defense load but what do I know.