We have a .450 Marlin on an Ultra that my better half used last year for primitive weaoins seasin here in MS. I mounted a Swift fixed 4X scope on it and she got a nice freezer ready doe with it. I reload so I can pretty much tailor her loads for recoil. If you reload you can load any thing in the 450 that you can in a .45-70 (that is, you can "down-load" it the same way). For her, I'm loading 40 gr Reloader 7 behind a Remington 300 gr HP corloc bullet for aboiut 1700 fps as best I recall right now. We've had no problem with sticking cases but, in other calibers, that's always been easily solved by polishing the chamber a little with Flitz. I "floated" the barrel for her with seven or eight layers of little 1/2" x 3/16" of maskint tape fore and aft of the forend screw slot, installed a Mercury Recoil Reducer in the buttstock, and the rifle is very accurate with the load I mention here and several cast bullet loads I also made up. I expect you'lll enjoy the rifle.
Best Regards,
stuffit