I was just going to have the 458 SOCUM pair with my 45-70 of which I have 3. The 45-70 is a good deer/pig/black bear rifle. I'm sure bigger game as well, but those 3 are the biggest we have around here. But tthe 450 Bushmaster has given me better kills than the 45-70. The bullets are just softer. You have to be careful with bullet selection with the 45-70.
Case in point. I shot a deer a few years back with a 350 grain bullet out of the 45-70. Broadside at about 60 yards. Double lung just missed the heart. The 350 grain bullet did not expand. Just poked a finger sized hole through the deer. I recovered the deer. It ran into a pine thicket swam a creek and expired on the far bank. Went about 100 - 150 yards. Had I been using a 300 grain hollow point, I doubt the deer would have taken 3 steps. Don't get me wrong. The 45-70 is poison on deer. Just use the right bullet. I like any of the 300 grain hollow points and the Speer 400 grain soft point is a good soft bullet too.