The KGM R556A1 Black is a quick-detach suppressor for 5.56mm and 6mm rifles (brand part no. RS-R556A1-QD-BLK). KGM designed it to meet and exceed SOCOM specifications for full-auto firing, accuracy, repeatability and minimal effect on the rifle’s operating system, and it has passed more than 20 SOCOM SURG firing cycles. The Inconel core and stainless components are laser welded, then gas-nitrided in-house. It works on 5.56 rifles of every barrel length and is ideal on 14.5-inch and longer barrels. At 4.85 inches, it is the short member of KGM’s hard-use 5.56 pair, a good match for an AR-15 carbine.

Key Specifications

• The caliber rating is 5.56mm and 6mm cartridges, including 6mm ARC since KGM opened the bore in 2024.
• Construction is Inconel and hardened stainless steel, laser welded for aggressive full-auto firing schedules.
• Length without the mount is 4.85 inches, per KGM.
• Weight without the mount is 15.9 ounces, per KGM.
• The mount is a quick-detach design with a tapered shoulder and secondary retention, for solid lockup and quick removal.
• The kit includes one 1/2×28 QD flash hider, the standard AR-15 muzzle thread.
• The finish is Black C-Series Cerakote, rated by KGM up to 1200 degrees Fahrenheit.
• Diameter is 1.75 inches, a standard rifle suppressor width.
• KGM applies an in-house gas-nitride finish to harden the suppressor.
• The bore is cut by wire-EDM, for alignment and concentricity.

Frequently Asked Questions

Do I need ATF approval to buy this? No. As of October 9, 2026, ATF no longer requires Form 4 approval, registration or a tax stamp for suppressors. It transfers on a Form 4473 with a background check through a Class 3 (SOT) dealer. State and local laws still apply.

What barrel length suits the R556A1? KGM says it works on 5.56 rifles of every barrel length and is ideal on 14.5-inch and longer barrels.

How durable is it? KGM reports it surpassed more than 20 SOCOM SURG firing cycles and was built to handle M855A1 from barrels as short as 6.5 inches.

Buy the KGM R556A1 5.56/6mm Quick-Detach Suppressor, Black

As of October 9, 2026, this suppressor transfers on a Form 4473 with a background check at your Class 3 (SOT) dealer, with no Form 4 or tax stamp; state and local laws still apply. Order through KGM Technologies‘s AR muzzle device and suppressor lineup and our Lubbock, Texas team will handle the transfer.