Just received my Winchester m54, it was sold to me as a 22/250, but a 22/250 shell won't chamber. It has an aftermarket barrel with no markings at all. The bore does look like it is .22. What would be the procedure for sizing the chamber? Can a gunsmith do this by a process of elimination, or is the barrel going to have to be removed and a casting be done? In witch case, it may actually be cheaper to buy and install a new barrel. Especially since it may be in a calibur that doesn't interest me.
Thank You For Your Time