Factory Rem 700VLS, one piece Ken Farrel base, Badger rings, Leupy VX 3 upgraded with M1 knobs. This rifle consistently prints .5 MOA at 100yds with 175gr SMK's, but accuracy goes to hell out to 500 & beyond. To my knowledge,I have checked all possible potential obvious flaws. I bought this gun when I was green, and never checked the bore before I bought it. There is a flaw in the bore about an inch down the tube from the throat where some of the rifling is gone, for about 2" in just one cut. I never bugged Remington about it because I was so impressed with the groups at 100yds. Now that I am shooting 500+, I am looking at a barrel replacement. I am thinking that the barrel is deforming the bullets and it's not showing up til way downrange. Any input?