A friend of mine has a 6mm Rem factory varmint that shoots sub 1/2 moa groups, and the barrel looks like a blacktop road for about 4-5" up the throat. Go figure. The only thing I can see is the action is warped so that the bolt cams into a tight seat when closed, judging by the wear marks on the bolt, and putting a straightedge along the action side. Bought it used, owner said he didn't shoot it much----yeah, right.