Completely absurd - Precision Armament M4-72 Severe-Duty Compensator

This brake performs exactly as advertised. Recoil be gone, and very much gone it is. It's blast to shoot, pun fully intended. Loud, obnoxious, you probably don't need it, but you should absolutely have it. The only downside I could come up with is the gas that gets sent straight into your face, but it's really not that bad.