I redid a Ruger No. 3 to .450 C&W (a rimmed .450 Watts) using a .458 Winchester Magnum barrel from a No. 1. I fitted it with a .45-70 extractor to accomodate the rimmed case (brass is necked up .375 H&H Flanged) and discovered to my surprise that the rifle now accepts, extracts and ejects .450 Watts belted cases as well. As I restrict my loadings to .458/.450 NE performance, the recoil is not a problem and the pressures are commensurately low.