Guys I am fighting a 284 that likes to throw a round out to the left about every other group. I was testing at 600yds and was shooting .5 moa groups on average. (This is my tactical rifle and I am not shooting off a bench.) About half of my groups will have a flyer off to the left. It will keep 4 around 2.5"s or so. This is driving me crazy!! I did get some brass from my old rifle mixed in with the brass for this one but its all FL sized so I can't see where it would be a problem. Now if I try to shoot the brass from this rifle in my old one I know it right away because I have some heavy drag on the bolt but not with the new one. The flyer can be anywhere from a couple of inches to 4 or 5"s It has on occasion thrown one low about the same distance. I shoot 162 AMAXs but have tried 175s in it and get the same results. Its a Bartlen barrel in light varmint contour, bedded into a fiberglass stock, with a MK 4 4.5x14 for optics. Any ideas you have would be appreciated.