No reason it couldn't be. Up to Ruger, I guess. I really liked my .458 Americans (2"). I had 3 of them over the years, first 2 on Mauser actions, VZ/34 and a Mark 10. The last one was on a Model 70A action.
My loads, when tried in a Siamese Mauser .45/70, gave identical velocities in a 24" bl. as I was getting in my 22" bl. with the 1/10" shorter case, however I did seat the bullets out considerably.
I feel they should not have made the .450 Marlin with the longer headspace than normal belted cases. Of course, that makes you need proprietary Marlin brass.