Thanks Jim, this is likely the route I'll take. Actually, it'll be solving a problem that doesn't exist unless you look really, really close. A month or so before all the AW b.s. started I spotted an Action Arms Uzi Model B carbine in our local gunshop, and for reasons which escape me it followed me home. Evidently at one point in its life someone had fired a round in a really dirty barrel, because there's a barely perceptible very shallow ring in the bore about halfway down the tube. No bulge on the outside. Bought a new tube from Numrich, but Uzi barrels are serial numbered to the rifle, so I'd like to keep everything original - it's just that ARGH! barely visible ring! Thanks again for the information.