I have heard one of his .223 cans in action, pretty much removed the muzzle blast, but the sonic crack is still loud enough to want to wear ear plugs. Kind of like a small firecracker, if you were 50 feet away it was no big deal at all. The one of his I shot was on a Ruger 77/44 bolt gun. Now that was impressive with 300gr. loads going subsonic. Click, hiss of the bullet flying, Thump! when it hit. Cloverleaf groups at 100 yds as well. Very neat!