I'm cleaning this gun up for a friend. Disassembled for cleanup and inspection. I noticed what looks like a "ring" inside the barrel about 10" back from the muzzle. There is also a slight bulge in the barrel in the same place on the outside. Hard to picture but if you look you can see it. I see no cracks or any other issues. It almost looks as if the factory joined 2 pieces together in this spot??? Anyone else have one that looks like this, or do I have a problem? Bore otherwise looks fantastic. Gun is said to be a good shooter, i've never shot it.