I hate to hear the uninformed claiming that the 45-70 is overkill for deer. I load mine with a 300 grain hornady hollow point. Accurate 2015 and getting aroung 17-1800 fps out of it loaded about medium. Thats the same size bullet and ballistics as a thompson center Omega with a 150gr powder charge. Is a 50 cal smoke pole overkill? No? Then why is a 45-70? Hmm....
It's about the same thing as having a repeating smoke pole. Sounds good eh?
Good buy on the 30-30. It'll do you right. It just won't be as fun as the 45-70.