So I ordered a Grizzly Gun Works muzzle brake got the Defcon 1. The barrel on my 300Wby was to light I figured to have it threaded so I got a clamp on brake. When I orderedit I was told it would be about 30 days to received it. So imagine my surprise when I got an email 14 days later saying it had been shipped. I got it and mounted it right away the fit is very snug. As of now I have only put 2 rounds through it but the recoil reduction is out of this world. My 2 shots were off hand at the shot recoil was almost nil and the muzzle actually seemed ro push down. Some friends and I are going out to sight our guns in today and I will be firing it off the bench with a better report to follow. So far I would recomend one of these brakes.