The Chaos Gear Supply Helios QD 5.56mm Inconel Suppressor is a kit-style rifle can built from 718 Inconel and 17-4 stainless steel (CGS part no. CGS-HELIOS556-QD). It is designed for 5.56mm rifles and carbines but bored out to .36, which lowers back pressure and flash and lets it handle far larger cartridges. A taper interface between the muzzle device and the can helps prevent carbon lock. Both 1/2×28 and 5/8×24 rear caps and a 1.375×24 adapter ring come with it. The Inconel build is full-auto rated with no barrel length restriction.

Key Specifications

• The design caliber is 5.56mm, and CGS rates the can up to and including 300 Norma Magnum.
• Weight is 19 ounces in the Inconel build, as the dealer listings give it.
• Diameter is 1.75 inches, a standard size for handguard clearance.
• Length added to a bare muzzle is 6.5 inches, and 4.9 inches over a muzzle device.
• The materials are 718 Inconel and 17-4 stainless steel, chosen for heat and strength.
• The bore is .36 diameter, which cuts back pressure and muzzle flash.
• Rear caps in 1/2×28 and 5/8×24 are included, so one can fits both common muzzle threads.
• A 1.375×24 adapter ring is included for use with a range of mounting systems.
• The can is full-auto rated with no barrel length restriction.
• A lifetime warranty from CGS covers the can.

Frequently Asked Questions

Is there a barrel length restriction? No. The Inconel Helios QD is listed as full-auto rated with no barrel length restriction, and it handles calibers up to and including 300 Norma Magnum.

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 mounts and caps come with it? The kit includes 1/2×28 and 5/8×24 threaded rear caps, interchangeable front caps and a 1.375×24 adapter ring.

Buy the Chaos Gear Supply Helios QD 5.56mm Inconel Suppressor, 19 oz

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 Chaos Gear Supply‘s silencers and suppressed firearms lineup and our Lubbock, Texas team will handle the transfer, and it ships fast to your Class 3 dealer. It is the heavier, full-auto-rated Inconel version of the Helios QD for hard use.