Here is a gun that started life as an Argentine Mauser chambered in 7.65 Argentine. It has been sporterized and rebarreled but the barrel has NO markings on it to identify the caliber. Measured at the muzzle with a micrometer and came up with, "possibly .243win or .257 roberts, but do not quote me on that, I've never had to measure out what caliber a rifle is." We have set the price to reflect the anonymity of this rifle.