I know it's not a rifle, but I picked up a well-loved CZ-70 handgun recently and noticed some oddness in the barrel. After shooting today, it seemed like there was a ring of crud about 1/2" in front of the chamber. I thought the barrel might be ringed from a prior squib, but the location corresponds to the end of where the barrel is pressed into the frame. Has anyone else got one of these with this eccentricity? Could this be from the manufacturing process?

Don't know whether I'll deal with it: pistol seems to shoot well with jacketed as the barrel is. Will probably depend how it does with PC boolits.