Shop › SCO ASR MB SINGLE PORT 1/2"X28 9MM SCO ASR MB SINGLE PORT 1/2"X28 9MM $79.90 SilencerCo Single Port ASR Muzzle Brake, 1/2 x 28 RH, Fits ASR Mounts, 9MM AC2628 Quantity: Add To Cart Added! SilencerCo Single Port ASR Muzzle Brake, 1/2 x 28 RH, Fits ASR Mounts, 9MM AC2628