I have been given a rifle barrel, I can choose the caliber. This is an ideal opportunity to re-organize my hunting rifle battery. Currently I own a 6.5x55, a 6.5 Creedmoor, a 7x57, a .300 win mag and a .303. The Creedmoor has a heavy barrel, the others are all normal sporters. I have decided to get rid of the .303, it is going back to its previous owner, as soon as he gets dedicated status.

The creedmoor is brand new (in fact I am still waiting for the license card) so it will stay as is and the 7x57 is my wife's rifle so it is untouchable. This leaves me either the 6.5x55 or the .300 win mag to re-barrel. I want a medium caliber which is legal for buffalo, in most countries both the 9.3 and the .375 are. My initial idea was to re-barrel the .300 to a .375 (either Ruger or H&H), however, between the .300 and the 6.5 Swede I'd rather have the .300 win mag. Another option would be to re-barrel the Swede to 9.3x62. Re-barreling the Swede to .375 would require opening the bolt face and probably some other work, will this be feasible?