Brother has a sporterized Mauser he can’t figure out the caliber of. It was inherited. Whichever gunsmith did the work never marked the barrel or receiver anywhere with what the gun is chambered in. I feel like it may be a .243 but don’t have any ammo to try and I sure as hell ain’t gonna just shoot something out of it just cause it fits in the chamber. anyone in the OKC area that could give a positive ID on the caliber and possibly laser etch or engrave the caliber somewhere on the gun?