Comstock Armory .223/5.56 Quick Detach Recessed Plan-B HUB Suppressor Mounting Kit

Comstock Armory .223/5.56 Quick Detach Recessed Plan-B HUB Suppressor Mounting Kit

The Comstock Armory .223/5.56 Quick Detach Recessed Plan-B HUB Suppressor Mounting Kit pairs two 1/2x28 recessed micro muzzle brakes with one steel RPA HUB adapter. Built around matching Comstock components, this specialized mounting package gives two compatible AR-15 or other .223/5.56 firearms a common Plan-B interface for sharing one compatible suppressor.

This kit contains everything you need in mounting hardware to mount your compatible HUB suppressor to multiple AR-15s or .223/5.56 firearms with 1/2x28 threads while keeping an ultra-tight, low-profile mounting system. The included pair of muzzle brakes equips two firearms.

Shop this Comstock Armory 5.56 mounting kit at BattleHawk Armory for a compact Plan-B setup across two compatible firearms.

Kit Contains

• 2x Comstock Armory Recessed Micro Plan-B Muzzle Brake, 1/2x28, 5.56, Black Nitride - SKU: MBM-12-22-R - UPC: 850069580308
• 1x Comstock Armory RPA HUB Recessed Plan-B Suppressor Adapter, Stainless Steel - SKU: RPA-B-SS - UPC: 850069580285

The package contains three mounting components: two muzzle brakes and one suppressor adapter. Firearms and a suppressor are not included.

Recessed Plan-B HUB Mounting

The RPA-B-SS adapter connects a compatible 1.375-24 HUB/Bravo suppressor to the included Plan-B-pattern muzzle devices. Its recessed profile positions the muzzle device 0.40 inch deeper than the standard Comstock LPA, shortening the assembled mounting configuration and helping create a tighter handguard-to-suppressor gap. The adapter itself adds 0.18 inch of length and weighs 2.1 ounces.

One adapter serves the compatible suppressor while the two brakes provide matching attachment points on two firearms. Quick-detach convenience and the recessed profile work together for a compact system. Actual spacing depends on the firearm, muzzle device and suppressor combination.

Two 1/2x28 Brakes for .223/5.56 Firearms

Both included MBM-12-22-R brakes use 1/2x28 barrel threads and are sized for .223/5.56 projectiles. Each brake measures 1.25 inches overall, adds 0.42 inch beyond the muzzle and weighs 1.5 ounces. The matched pair is a practical choice when two compatible AR-15s or other .223/5.56 firearms need the same compact suppressor interface.

The recessed micro brake design reduces recoil and acts as a sacrificial surface ahead of the suppressor blast baffle. Its rotationally symmetric geometry does not require timing with shims. Limited forward protrusion is useful with the recessed adapter, while the complete combination still requires adequate internal clearance.

17-4 PH Stainless Steel and Black Nitride

Both muzzle brakes and the RPA adapter use 17-4 PH stainless steel with a black nitride finish. The kit pairs professional-grade steel components with a consistent black appearance. The included adapter is the steel RPA-B-SS configuration, with the same material and finish family as the recessed micro brakes.

Compatibility and Clearance

Both firearms must have compatible 1/2x28 muzzle threads and a barrel diameter of 0.750 inch or less where the recessed brake overlaps the barrel. The .223/5.56 brakes are not intended for larger projectiles. The suppressor must have a compatible 1.375-24 HUB/Bravo rear interface and an appropriate cartridge and barrel-length rating. Confirm blast-chamber and handguard clearance for each complete configuration.

Product Specifications

• Component manufacturer: Comstock Armory
• Configuration: .223/5.56 Recessed Plan-B HUB Mounting Kit
• Included hardware: Two recessed micro muzzle brakes and one steel RPA adapter
• Barrel threads: 1/2x28 on both muzzle brakes
• Caliber / bore limits: .223 / 5.56mm
• Suppressor rear interface: 1.375-24 HUB/Bravo
• Muzzle-device interface: Plan-B pattern
• Material / finish: 17-4 PH stainless steel / black nitride
• Brake length: 1.25 inches overall; 0.42 inch added beyond the muzzle
• RPA profile: 0.18 inch added adapter length; muzzle device sits 0.40 inch deeper than with the standard LPA
• Maximum barrel diameter at brake recess: 0.750 inch
• Component weights: 1.5 oz per brake; 2.1 oz adapter

Frequently Asked Questions

Can this kit equip two AR-15s?

Yes, the kit supplies two .223/5.56 brakes with 1/2x28 threads for two compatible firearms, plus one adapter for a compatible HUB suppressor. Each firearm still needs sufficient barrel, handguard and internal suppressor clearance.

Does this package include two suppressor adapters?

No. It includes two muzzle brakes and one RPA-B-SS adapter. The package supplies two firearm-side mounting points for one compatible suppressor.

Does HUB threading alone guarantee fit?

No. Matching rear threads are one requirement. The recessed mounting position also requires suitable blast-chamber depth, handguard clearance, barrel dimensions and caliber compatibility.

Order the Comstock Armory .223/5.56 Quick Detach Recessed Plan-B HUB Suppressor Mounting Kit from BattleHawk Armory. Bring matching recessed components together in one specialized package for your two compatible firearms.