BAR rebrl.
I had one in 300 WM rebrled to .458WM, it was done by a man in Ont. that has since moved to the US, it worked very well with spitster bullets, it did not feed well with flat nose ones, but alas i sold it I think it is in BC somewhere. It was quite a thumper 3 - 450X 's as fast as you could pull the trigger,it was about 11 pounds as the SS brl. was left at about .9 in. at the muzzle. So I know it can be done.
take care
pounder