Your biggest challenge will be reliable feeding in a magazine rifle. WRT to accuracy, only testing will reveal the answer. Chamber damage? You’re using short brass when using the win mag vs the Lott brass, so there will be hot gasses in direct contact with parts of the chamber between the short case mouth and the leade that would not normally see hot gasses. I can’t imagine it would cause you any significant damage, after all, we’re not talking about a high round count target rifle..are we? I’ve shot a few dozen rounds of .458 Win Mag in a couple of Lott chambered rifles with no discernible Ill effects and with reasonable if not stellar accuracy. I did it for the simple reason to see if it could be done in a pinch. If you are doing it for lighter loads for practice, simply use Lott brass and load light charges as per your reloading manuals. Lott brass is very common and there is really no reason to shoot win mag in it save for the rare occasion your luggage/ammo doesn't show up courtesy of the airlines.