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HUXWRX FLOW 556k vs Dead Air Sierra 5

By Cole Harlan, EditorUpdated Nov 5, 2026How we verifyEditorial standards

Both are 5.56-class rifle suppressors on different mount systems. HUXWRX lists the FLOW 556k at 12.9 oz and 5.5 in, with a Torque Lock mount. Dead Air lists the Sierra 5 at 10.8 ounces and 4.87 inches with no adapter (13.3 ounces and 5.72 inches with Xeno). Figures are copied from each maker’s own page, checked November 5, 2026.

At a glance

Spec (maker label)	HUXWRX FLOW 556k	Dead Air Sierra 5
Caliber (maker wording)	Compatible on 5.56, 17 HMR and 5.7 platforms	5.56 NATO, 224 Valkyrie
Energy rating	Not yet verified	2200 ft. lbs
Length	5.5 in	4.87 Inches (no adapter); 5.72 Inches (w/Xeno)
Diameter	1.6 in	1.5 inches
Weight	12.9 oz	10.8 ounces (no adapter); 13.3 ounces (w/Xeno)
Materials	Fully 3D-printed in 17-4 stainless steel; Flow-Through® and Torque Lock®	Cobalt 6 baffles, stainless steel
Finish	C-series high temperature Cerakote	Black Cerakote®
Full-auto rated	Yes	Yes
Barrel restrictions	Not yet verified	None
Mount (as described)	Compatible with Muzzle Brake-QD 556 and Flash Hider-QD 556	HUB compatible (1.375-24”); available with KeyMo or Xeno out of the box
Printed MSRP	$1306, for a kit (one FLOW 556k + one Flash Hider QD 556 1/2x28)	$859 (Specifications block); store listing $899.00 – $979.00
Source (checked Nov. 5, 2026)	huxwrx.com/flow-556k	deadairsilencers.com Sierra 5

Like for like: the mount systems differ (HUXWRX Torque Lock QD against Dead Air HUB, KeyMo or Xeno), so the Sierra 5 “no adapter” length and weight are not the same basis as the FLOW 556k figures, and we compute no gap. The Sierra 5 KeyMo length and weight are not yet verified. The FLOW price is a kit price that includes a flash hider, while the Sierra 5 prints $859 in its Specifications block and $899.00 – $979.00 in the store listing, so we make no single cheaper claim. Neither page gives a decibel figure that we use, so we draw no sound comparison. Suppressors are NFA items; see how to buy a suppressor.

Which to pick (on paper)

If the lowest listed weight and length matter: the Sierra 5 at 10.8 ounces and 4.87 inches with no adapter, against 12.9 oz and 5.5 in for the FLOW 556k. With Xeno the Sierra 5 is listed at 13.3 ounces and 5.72 inches.
If the slimmer tube matters: the Sierra 5 at 1.5 inches against 1.6 in.
If you already own the mount hardware: match the system: Torque Lock QD for the FLOW 556k, or HUB, KeyMo and Xeno for the Sierra 5.
If you also shoot 17 HMR or 5.7: HUXWRX lists the FLOW 556k as compatible on those platforms; Dead Air lists the Sierra 5 for 5.56 NATO and 224 Valkyrie.
If a printed energy rating or no-barrel-restriction statement matters: only the Sierra 5 page lists them (2200 ft. lbs; none).

We have not range-tested these; facts above are from the makers.

Not yet verified

Sierra 5 length and weight with the KeyMo adapter.
FLOW 556k energy rating and barrel restrictions, and a can-only price.
Decibel figures for either can.

Frequently asked questions

How heavy are the FLOW 556k and Sierra 5?

HUXWRX lists the FLOW 556k at 12.9 oz. Dead Air lists the Sierra 5 at 10.8 ounces with no adapter and 13.3 ounces with Xeno.

Are they full-auto rated?

HUXWRX lists the FLOW 556k as full-auto rated (Yes). Dead Air lists the Sierra 5 as full-auto rated (Yes) with no barrel restrictions.

What do they cost?

HUXWRX prints $1306 MSRP for a kit with one FLOW 556k and one Flash Hider QD 556 1/2x28. Dead Air prints $859 for the Sierra 5 in its Specifications block, and its store listing shows $899.00 to $979.00. These are maker-printed prices, not street prices.

HUXWRX FLOW 556k vs Dead Air Sierra 5

At a glance

Which to pick (on paper)

Not yet verified

Frequently asked questions

Sources

Keep exploring

At a glance

Which to pick (on paper)

Not yet verified

Frequently asked questions

Sources

Keep exploring

The Gun Release Report