I am talking about a bolt action. I was not referring to the BLR, in which that option is available, but rather someone who had acquired a bolt rifle chambered in one of the Winchester Short Magnum cartridges. That is the "WSM" I was referring to.
If one were to want a heavier cartridge, he could simply remove the original barrel and fit a new barrel chambered in .450 Marlin, load that cartridge to pressure levels higher than the Marlin platform will allow, and enjoy the performance gain. The only hiccup might be the need to slightly adjust the lips of the magazine.
I really don't know schidt from shineola about a BLR, having never owned, fired, or worked on one, though I do like the thought of one in .358 Winchester. I have rebarreled numerous bolt rifles, though.
