Breek Arms Sentinel Closed Tine Plan B Flash Hider 223 Remington 556NATO 1 2X28 Compatible With Plan B Rearden Matte Finish Black BRK4420 UPC 812296031763
Product Description
The Breek Arms Sentinel Closed Tine Flash Hider (BRK4420) is a high-performance suppressor adapter and muzzle device engineered for .223 Rem / 5.56mm NATO rifles. Designed around the popular Plan B mount geometry, the Sentinel provides full compatibility with Q® Plan B and Rearden Manufacturing suppressor quick-detach (QD) mounting systems, offering shooters a lightweight, rock-solid interface for fast suppressor attachment and detachment.
Precision-machined from heat-treated 17-4 PH stainless steel, the Sentinel features a closed-tine architecture that drastically reduces muzzle flash signature while eliminating the annoying ringing sound often associated with open-prong flash hiders. The closed-bottom geometry acts as a natural compensate-style force break, reducing muzzle rise and preventing dirt/dust kickup when firing from a prone staging position.
Finished in a resilient, non-reflective black nitride (QPQ) coating, the BRK4420 resists carbon buildup, extreme thermal cycles, and harsh environmental corrosion. Threaded in standard 1/2"-28 UNEF right-hand pitch, this muzzle device features precision taper alignment surfaces that guarantee concentric lockup with Plan B pattern suppressor mounts, protecting against baffle strikes on suppressed tactical rifle setups.
*Armorer Bench Notes & Real-World Staging Guidance:*
Fitment Matrix: Threaded 1/2"-28 UNEF for .223 Rem / 5.56 NATO barrels. Compatible with Q® Plan B, Rearden Atlas, and all Plan B-pattern QD suppressor mounting hubs.
- Ensure the rifle is completely clear, magazine removed, and chamber visually and physically verified empty.
- Clean and degrease the barrel muzzle threads thoroughly using isopropyl alcohol or solvent.
- Apply a high-temperature threadlocker (Rocksett recommended for suppressor mounts) to the 1/2"-28 muzzle threads.
- Thread the Sentinel flash hider onto the barrel and torque to 25–30 ft-lbs using a dedicated muzzle device wrench applied to the wrench flats. Allow 24 hours for Rocksett cure before mounting suppressors or firing.
Key Features
- Plan B & Rearden QD Compatibility: Taper-mount geometry locks up seamlessly with Q® Plan B and Rearden Atlas suppressor mounts.
- Closed Tine Flash Suppression: Suppresses signature flash without pinging/ringing sounds common to open-prong designs.
- 17-4 PH Stainless Steel: Precision CNC-machined from heat-treated stainless steel for extreme thermal and pressure resistance.
- Black Nitride (QPQ) Finish: Smooth QPQ coating provides high corrosion protection and easy carbon cleaning.
- Closed-Bottom Design: Eliminates prone dust kickup while assisting with flat muzzle control during rapid fire.
Product Specifications
- Brand: Breek Arms
- Model/Series: Sentinel Closed Tine Flash Hider (Plan B Series)
- MPN / SKU: BRK4420
- UPC: 812296031763
- Caliber Compatibility: .223 Remington / 5.56mm NATO
- Thread Pitch: 1/2"-28 UNEF RH
- Mount Standard: Q® Plan B / Rearden Compatible Taper Mount
- Material: 17-4 PH Stainless Steel
- Finish/Color: Matte Black Nitride
- Country of Origin: United States
