They work exactly as advertised. The original muzzle brake style seems to me to reduce felt recoil (M70 300 WM) and it's LOUD. Never tried the BOSS CR (conventional recoil/non-ported) but word has it they also work, without the loud part. I think they're cool but can see that they detract from the looks of a classic walnut & blued steel rifle. Mine's a stainless & synthetic so it doesn't make much difference. -WSJ