Thread: 7x57

Whoever chambered that barrel owes you a new barrel.

But you could still use it like it is. It may not be a big deal. If you dont get case head separations on the first firing (which I m betting you wont) there is not much wrong with it really. Once the brass has been once-fired just neck size the cases and reload for it like normal. You'll just have a 7x57 with a generous chamber. Like every .303 ever made.