Is this a common thing on some military rifles? I have 03A3 that the bbl is what I call frosted the full length. One does not hardly see it when looking down the bbl, but when you run a patch you can feel it the full distance. The rifle is one very accurate shooter. The fella I got it from told me the Lyman 311335 was the best shooting bullet , he wasn't kidding. The bore is excellent, except for this "frosting".
bob