I have a friend with one in 7mm Rem Mag. This fall before hunting season we took it to the range to test different brands of ammo and see how well the rifle shoots. It was quite an interesting time we discoverd that the rifle shot Barnes 160 ammo Hornady 160 superformance and Hornady 160 sst ammo all to the same point of impact. The groups were all around the same size 1.5 inches. He may also have shot some Remington 160's as well. All of his shooting was done without the muzzle brake. He had it with him one time in the summer and used it but I can not remember if he said it made a big difference. All in all it seemed like the gun is a pretty good performer from what I saw. When we were shooting the groups we let the barrel cool for at least 8 minutes between shots it was a cool day and the barrel was cold to touch each shot.