read tony boyer's book and used my new hawkeye and discovered CARBON RINGS in several guns. he suggest inserting a bronze brush one size larger than the caliber into the neck portion of the chamber and rotate multiple times then inspect with the scope. this works but the brass wears easily. tried a hoppe's product call tenex brush..very stiff ? plastic and it seems to hold up nicely, esp with a little jb on the tip. this baked on ring of carbon is tenacious! it occ comes off in bits and pieces. if left alone how deleterious is it to accuracy? boyer blames it for what he calls "stupid shots"...a flyer for no descernible reason. measured some 6x47 lapua brass and found a difference of .008 thous. if the shorter cases are fired first, they lay down a ring of carbon. chamber the longer cases and they have to impale the .008 of carbon which boyer feels can add more pressure to the neck and possibly result in more neck tension and affect accuracy. i can see this happening. i have felt an occasional tight chambering and assumed that case wasn't sized enough. could this have been a longer case's neck hitting the carbon ring? l will pay more attention to trimminmg my cases to the same length and see if a previous accurate load that for some reason won't shoot, begins to group tighter. so, carbon rings. anybody?[/quote] if i can see you, i can touch you. BANG!