The Griffin Dual-Lok HRT-556 FDE is the flat dark earth version of the shortest suppressor in Griffin Armament’s Dual-Lok family, a 5.56mm can first designed for elite HRT units (Griffin part no. GADLHRT5FDE-W). The body and most baffles are 17-4 stainless steel heat treated to H900, with a 718 Inconel blast baffle taking the hardest hit at the muzzle. Griffin’s ECO-FLOW baffle stack keeps backpressure down, and a low-profile flash-reducing end cap trims first-round flash without adding much length. The Dual-Lok mount locks to the muzzle device through a taper and a toothed locking ring, with no consumable parts to wear out. It is a short, hard-use choice for an AR-15 carbine or a short-barreled 5.56 build.

Key Specifications

• Overall length is 6.3 inches, the shortest of the Dual-Lok 5.56mm cans and a good match for a short carbine.
• Weight is 16.0 ounces, a sensible figure for a hard-use rifle suppressor with an Inconel blast baffle.
• Construction is 17-4 H900 stainless steel with a 718 Inconel blast baffle, chosen for heat and erosion resistance under sustained fire.
• The mount is the Dual-Lok system, a taper lock with an ACME thread and a locking ring with 3 anti-rotation teeth for 120 effective positions.
• A Dual-Lok Minimalist Brake in 1/2×28 comes in the box, so the can is ready for a standard threaded 5.56 barrel.
• The finish is FDE Cerakote, a flat dark earth coating that suits a tan or earth-tone rifle.
• It is full-auto rated and rated up to .22-250 Remington, with no barrel length restriction for rifle calibers.

Frequently Asked Questions

Which Dual-Lok muzzle devices will not work with the HRT-556? Griffin states that the HRT-556 is not compatible with the Dual-Lok Stealth Flash Suppressor in the 2.75-inch length or the Dual-Lok Bayonet Flash Hider. The 2.25-inch Stealth Flash Suppressor, the Minimalist Brake and flash suppressor, the Tactical Compensator and the 2 Port Paladin Brake are listed as compatible.

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.

How short a barrel can I run it on? Griffin lists no barrel length restriction for rifle calibers with the HRT-556, and its published sound figures include an 11.5-inch carbine.

Buy the Griffin Armament Dual-Lok HRT-556 Suppressor, 5.56mm, FDE

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 Griffin Armament‘s silencers and suppressors lineup and our Lubbock, Texas team will handle the transfer, and it ships fast to your Class 3 dealer. Griffin backs it with its Perpetual Lifetime Warranty.