I have a .50 cal barrel and had problems with it grouping, but it ws not the barrel, it was the load, and the bullets, got that straight shoots great, have a shotgun barrel, shoots great and a .223 barrel, which I took to WY for Prairie Dogs, shot cheap ammo and killed dogs to 400 yards and impressed guys with me that had custom builds, great gun. I would first look at how a scope and rings and bases are mounted. Having seen a variety of problems that people deal with I think this is usually the real problem. I mount my bases and rings to not move, period and have no problems.