That is probably a re-chambered .375H&H.

George

I think they chambered in .300Wby. briefly (and perhaps .270Wby. also), but I am not a 'R-ugh-er' aficionado .



When you look at the gun, it should be readily apparent whether it is a factory gun, re-chamber, or re-barrel by looking at the markings on the barrel.



Let us know what it turns out to be.



George