Bushmaster 14.5" barrel in the pictures has over 10 000 rounds through without any major cleaning. As you can see, the grooves and rifling are pretty badly fouled. Pictures are taken
after several hours of cleaning.
Light made it look like there is bad grooves on rifling but that is fouling build up.
Lots of shooting leaves marks also to the chamber area. Hard chrome is chipped from the chamber.
Business end of the barrel is like new from the factory.
Couple of pics taken from groups I shot
before I started to clean this mess. At this point there was about 9500 rounds through the barrel.
Groups were shot from 109 yds using bipod and sand bag as support.
10 shot group of 69gr SMK.
10 shot group of 77gr SMK. Not bad for the worn out barrel with 1/9" twist...
Needless to say, I´m big fan of chromelined barrels.
MN