338 RUM and .338 federal have nothing in common other than bore diameter. .338RUM is a shoulder busting, barrel burning, recoil machine suitable for game no smaller than Elk and best reserved for moose and large bear. .338 Federal is a short action, leisurely cartridge designed for medium distances. It could be an ideal brush cartrige if i could catch on.
Rechamber a savage 99 for a 338RUM and it will be scattered amongst the firing line in more pieces than you can count - other than the ones the dr will be pulling out of your arms, chest and face.