Question time again. I am shooting a W/Weaponry AR , 7.62 x 39, and just started seeing some odd scratches on the brass rim and body. The scratch runs from the rim and is noticeably deep, as in a little metal displacement, then tapers off as it runs up the body about .3" to .5" in a diagonal direction at first. As the scratch tapers off it also straightens out fwd to the mouth of the case. I replaced the extractor a while back but I don't think this is causing it as the scratch is travels fwd of the rim. I checked for corresponding wear marks on the magazines, one new and the other used ASC 10 rd. mags, and there are none. It appears that the lug in the barrel (feed ramp?) which engages the bolt at 6:00 position is causing the scratch. Looks like there is some metal transfer there but is tough to tell. Straight as the brass first contacts the lug and then spiraling as the bolt rotates during engagement and lock up. Most noticeable on Herter's ammo but also occurs on Winchester, PPU and Hornady brass. I am burning some steel case ammo through hoping it might dress down a possible burr on the lug. The scratches wouldn't be an issue except I reload and the scratch in the rim keeps the resized case from dropping in the case gauge unless I dress down the displaced rim mat'l. Also I have concerns about the body scratch being a stress riser causing premature cracks.
I have some pics attached of the brass and wonder what everyone's input might be.
As always may God bless and guide us all.