Shop › SCO THRD OVR MZL BRK 1/2X28 .223 CAL SCO THRD OVR MZL BRK 1/2X28 .223 CAL $79.90 SilencerCo Compact Radial Brake, 223 Remington/556NATO, Fits 1/2X28, Compatible with SilencerCo Thread Over Mounts AC5231 Quantity: Add To Cart Added! SilencerCo Compact Radial Brake, 223 Remington/556NATO, Fits 1/2X28, Compatible with SilencerCo Thread Over Mounts AC5231