at one time i had a photo of a Contender that had been wrecked by a .444...that may not mean much though, as there are LOTS of ways to tear up a gun, could have been a sloppy re-chamber, or maybe the handloads it was being fed were way over the safe limit. or who knows what else.
TC will not make & does not recommend the 444 in a Contender/G2...apparently it is over the line apparently in pressure, backthrust, etc...
i have 445 Supermags in a 12" Pistol, 14" Pistol, and 18" Carbine. its a nice caliber. i dont plink much with mine, not really a "plinking" caliber in my book..i would recommend you get a brake on it; i dislike the noise they make too, but i also dislike getting beaten up with recoil.
If you were feeding it a steady diet of 300 grain loads for hunting i guess a 444 would be a better choice...it simply has more case-capacity to handle large doses of powder to push the heavy bullet loads. Of course, those same large powder charges are what makes the 444 marginal in a Contender...plus they REALLY kick in light guns like the TC carbines, and if youre just punching paper you wont want to punch it a whole lot..
If you download the 444 to safe pressures, i suppose it would be fine, but i personally am not crazy about cartridges i have to download to keep from worrying about damaging my gun.. i do think the .445 has some good points over the 45/70 if you are shooting light bullets mostly, i use my 445's more on deer & the 45/70's on big stuff... hope that helps some..