i have a ruger mk2 vt in 223 and i'm getting marks on my brass around the head stamp area and getting brass filings on the bolt face it is distorting the primar pocket slightly. it does'nt seem to matter what load i use minimum or maximum. does anyone have any idea what's going on?

What does the bolt feel like when you chamber a round? Is it a little tight? Remove the firing pin from the bolt and chamber a round and have a look to see if the marks you are seeing are present. Look the bolt face over carefully for any burrs that may be the source for the shaved brass.

How does the bolt feel after you fire a round? Is the bolt handle easy to lift?