Morning (6:30 here) Meplat.
I appreciate your interest in helping me find the best barrel to suite my needs.
My short list became the 45-70, & the 450 Marlin. There wasn't much more info on SP or any other sites on the 450 in handguns (no shortage on 45-70 info).
From what I can find, they are just about balistic twins. No real advantage either way. I can shoot the same bullets at the same velocities in either one of them. Both should work good for big bear to 100 yds (150 on the "perfect opportunity"), & be a fine 200 yd moose & smaller critter cartridge, & I'm sure I can load either one up to levels that a recoil wimp like me will have no interest in.
Guys with both calibers say they get great accuracy, & once I have brass loading costs will be very similar. I don't currently have dies for either.
So, how will I make the decision between the two?
Well I carefully weigh the attributes of each, studying everything I can get my hands on,...... & then I'll buy whichever one I find at the best price.
I'm currently working on a deal for a 450 at a reasonable price, but if that falls through I'll still be watching for a good price on either one, & in the meantime will play with the .444 Contender.
On a note you'll appreciate, I've decided to go ahead & play with cast bullets with gaschecks in the Contender. I can see the brake manafactures liability concerns & covering his own tail, but I think you guys are right & it's a 1 in a million chance for a gas-check to hang up in there. I shot quite a few through there before his warning without problem, so I'm loading some up with 300 hardcast wfngc that I have on hand. If the 450 deal doesn't go through I'll pick up some 340s & play with them.