BFFire, where are you?
One test you can try is to put a piece of Duct tape on the base of a 308 win cartridge and insert it in the chamber and close the bolt. If it has resistance because the tape makes it too tight it's almost certainly a 308 win or a shell based on the 308 (338 Federal or 358 Win) but the 308 has a longer shoulder dimension then a 300 Savage so if it chambers, it's not a 300. If it works easily with a factory 308 cartridge and gits hard with the tape on it's base you have about 99.9% chance it's something based on the 308 shell and if the bore is 30 caliber you seem to have a 308 Win.
The 308 bullet will not enter the throat if it was a 7-08, 260 or 243.
The cartridge would not fit at all in a 30-30, 303 Savage, or 250 Savage.
Last edited by szihn; 02/23/21.
