Last year I bought a .458 Winchester Magnum barrel for the No. 1 Ruger off the internet, fitted it to a No. 3 Ruger action and had it rechambered to .450 C&W, which is my rimmed version of the .450 Watts Magnum, using .375 H&H Flanged brass and .458 bullets. I equipped the rifle with a .45-70 extractor.

Once, just as an experiment, I loaded a .450 Watts belted case into the chamber, and lo and behold, it not only fit, but fired and extracted perfectly. I now have a rifle which will cheerfully digest both rimmed and rimless belted cases, including the .458 Winchester Magnum cases it was originally chambered for. I refer to it as X-Caliber, since it will accomodate so many varieties. I haven't tried .410 shotshells, but I suspect they would function, too.