The Griffin GP-5 5.56mm suppressor is a tubeless direct thread can that screws straight onto a 1/2×28 muzzle with no separate mount in between (Griffin Armament part no. GAGP5-W). A laser-welded 17-4 stainless steel body wraps the company’s patented ECO-FLOW baffles, which are built to manage gas flow through the stack. Front and rear wrench flats let you torque it down with a standard wrench or set it up inside a rail, and a pre-drilled pin hole with a shim set is included for permanent pin-and-weld builds. Griffin rates the aperture for .22 caliber loads from 5.56mm up through .220 Swift, so it suits an AR-15 carbine and a varmint rifle alike. It is a plain, hard-wearing choice for range days and general carbine use.

Key Specifications

• The caliber rating is .22 caliber aperture, 5.56mm through .220 Swift, which sets the range of rifles it can serve.
• The mount is a 1/2×28 direct thread, the common pitch on 5.56mm barrels, so no muzzle device or separate mount is needed.
• Overall length is 6.25 inches, short enough to keep a carbine handy.
• Diameter is 1.5 inches, a typical rifle-can size for clearing handguards and sights.
• The body is laser-welded 17-4 stainless steel, chosen for strength and corrosion resistance.
• Construction is tubeless, with the baffles forming the outer wall to cut weight without giving up durability.
• The baffles use Griffin’s patented ECO-FLOW design, which manages gas flow to reduce blowback.
• Front and rear 3/4-inch wrench flats allow conventional tightening or a rail-integrated setup.
• A pre-drilled pin hole with a shim set is included for pin-and-weld installations.
• Griffin lists the can as full-auto rated with no barrel length restrictions, a plus on hard-use rifles.

Frequently Asked Questions

What thread does the GP-5 use? A 1/2×28 direct thread, so it screws onto a standard threaded 5.56mm barrel with no adapter. It is a direct thread can only, with no quick-detach mount.

Can the GP-5 be pinned and welded? Yes. It comes pre-drilled with a .125-inch pin hole and a shim set for pin-and-weld work, and Griffin lists a 10.5-inch minimum barrel for that build.

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.

Buy the Griffin GP-5 5.56mm Suppressor, 1/2×28 Direct Thread

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 suppressed firearms lineup and our Lubbock, Texas team will handle the transfer, and it ships fast to your Class 3 dealer.