I'm not an expert on carbine barrels and I don't mean to hijack your thread, but when I bought mine, I wasn't expecting anything but heavily used rifle. When I looked down the bore, I first thought it was worn smooth, but after I ran some patches down the barrel and removed about a half pound of Ethiopian topsoil, It looked much better. In fact, like yours. I posted on another forum and was told that it didn't look like it was fired much (if at all). I don't have an erosion gauge either, but mine will take a .300 pin gauge and will only take about 3/4" of a .301. It won't take .302 at all. Maybe they just set the carbines to Ethiopia and no ammo. My stock looks like it was used more as a club!