Hard to get a 30/06 chamber reamer to follow the 7.7 chamber by hand, look at the brass carefully to tell if it has not ballooned at the head. It may not though. Feeding rails may also give you trouble also if they were adjusted out to eagerly. Theirs some good gunsmiths in the woods of Pa. though. And if that fellow carried it after first day of buck morning, you may be surprised! Bore diameter is a little harder to tackle but you never know. Have fun.