Suppressor Mounts Explained: Direct Thread vs. Quick Detach vs. HUB

Last updated: October 26, 2026

Short answer: Direct thread screws the can straight onto your barrel. It is the lightest and shortest option. Quick detach (QD) puts a brake or flash hider on the gun and clamps the can to it, so one can moves between guns fast. HUB is not a mount type. It is a 1.375×24 thread on the back of the can that accepts mounts from many brands.

Buying the suppressor is the easy part. Then somebody asks “what mount are you running?” and the conversation turns into alphabet soup. SilencerCo’s own mount guide opens by saying choosing a mount “can sometimes feel like doing your taxes.” They are not wrong. Let’s untangle it.

Two separate questions: mount size and mount type

SilencerCo boils it down to two things, and we think that is the clearest way to say it:

• Mount size is the thread on the back of the suppressor. It decides which mounts the can will accept.
• Mount type is how the can attaches to your gun: direct thread, QD, 3-lug or piston.

Get those two straight and the rest is details.

Mount sizes, and where HUB fits

From SilencerCo’s guide:

• 1.125×28 (SilencerCo calls it Alpha). Most round pistol cans use it.
• 1.375×24 (Bravo, better known as HUB). SilencerCo says it is “the most widely used mount size across the silencer industry,” and that “other companies started calling it HUB.” Most centerfire rifle cans use it.
• 1.375×32 (Charlie). SilencerCo specific, built for hard use.

The big deal with HUB is choice. If your can has a HUB rear thread, you can screw on a HUB mount from a lot of makers. Dead Air, for example, sells a KeyMo HUB adapter (DA428), and its FAQ lists cans it fits from SilencerCo, Energetic Armament, YHM, CGS and Dead Air itself. Always check the mount maker’s fit list before you buy. We carry the Dead Air KeyMo HUB adapter.

Direct thread

The can screws straight onto the barrel threads. SilencerCo calls it the lightest and shortest option, with the fewest parts, and a favorite for bolt guns and precision rifles.

The catch on a semi-auto is walk-off. SilencerCo says it “can occur” if you do not tighten the can properly. Follow your maker’s torque spec. Dead Air’s FAQ, for example, says it has no specific spec for direct thread but not to exceed 30 ft. lbs.

Direct thread also means the can’s mount has to match your barrel’s thread pitch. Two pitches you will see a lot are 1/2-28 and 5/8-24. Dead Air ships its Nomad with a 5/8-24 direct thread insert and its Wolfman with a 1/2-28 fixed mount, per its FAQ. Check your barrel before you order anything.

Quick detach (QD)

With QD, a muzzle brake or flash hider stays on the gun, and the can locks onto it. SilencerCo’s ASR is a taper mount with a locking collar. Dead Air’s KeyMo works with KeyMo and KeyMicro brakes and flash hiders, and Dead Air calls it “a faster and more repeatable attachment method” than direct thread.

Why folks pick QD:

• One can, several rifles. Put a matching brake or flash hider on each gun and move the can as needed.
• Fast on and off.
• The tapered systems are built for repeatable mounting. Dead Air goes further and says in its FAQ that a QD system is “always superior to direct thread, no matter the action type.” That is a manufacturer’s opinion, but it tells you how they see it.

The trade-off is extra weight and length, and you are buying into one maker’s system. A KeyMo can wants a KeyMo-compatible device on the gun.

3-lug and pistons

3-lug is push and twist. SilencerCo says it is popular on pistol caliber carbines and subguns, and flatly not for high-pressure rifle cartridges.

Pistons, also called boosters or Nielsen devices, are for semi-auto pistols with a tilting barrel. SilencerCo calls them a must-have for most suppressed handgun setups. SilencerCo says that on a Browning-style pistol “you need a piston.” Dead Air’s FAQ says the same, and warns not to run a booster and piston on a fixed barrel unless you swap the spring for its fixed barrel spacer.

Bore size: the rule you never break

The can, its front cap and its mount all have to be rated for the bullet you are shooting. A .30 caliber can can usually shoot 5.56. The reverse is how you ruin a can. Dead Air’s FAQ: “Be sure to NOT shoot 7.62 through a 5.56 front cap!” Check the caliber list on the maker’s product page every time. Running .300 Blackout? See our .300 Blackout suppressor guide.

So which mount should you pick?

• One can on one bolt gun: direct thread keeps it short and light.
• One can on several ARs: a QD system with matching muzzle devices on each gun.
• A can you might use on more than one brand of mount later: a HUB rear thread keeps your options open.
• A 9mm pistol: a piston in your barrel’s thread pitch.
• A pistol caliber carbine: 3-lug or direct thread, depending on what the can supports.

What you need to buy

Suppressors no longer need a Form 4 (see ATF’s update to NFA transfer guidance), but they still ship to a licensed dealer in your state, and state law still applies. Mounts, muzzle devices and pistons are parts, and they ship like other parts.

Shop suppressors, suppressor mounts, pistons and parts and AR muzzle devices. If your rifle barrel is not threaded, our gunsmithing shop does rifle barrel threading. Building an AR? Our AR-15 builder checks that the muzzle device matches your barrel’s thread pitch and bore.

Frequently asked questions

What is the difference between direct thread and QD suppressor mounts?

Direct thread screws the can straight onto the barrel. It is the lightest and shortest setup. QD leaves a brake or flash hider on the gun and locks the can onto it, so one can moves between guns quickly. SilencerCo’s mount guide covers both.

What is a HUB mount?

HUB is a 1.375×24 thread on the back of a suppressor. SilencerCo calls it Bravo and says it is the most widely used mount size in the industry. A HUB can accepts HUB mounts from many makers, like Dead Air’s KeyMo HUB adapter. Check each maker’s fit list.

Is direct thread or QD better?

It depends on your guns. Direct thread is lighter and shorter, which suits one can on one gun. QD lets one can serve several guns. Dead Air says in its FAQ that QD is “always superior to direct thread,” but that is a manufacturer’s view. Pick what fits how you shoot.

Will a direct thread suppressor come loose?

It can. SilencerCo says walk-off “can occur” on semi-autos if the can is not tightened properly (source). Follow your maker’s torque spec. Dead Air says it has no set direct thread torque spec but not to exceed 30 ft. lbs (Dead Air FAQ). Check it during range sessions.

Do I need a piston to suppress a pistol?

For most semi-auto pistols, yes. Tilting barrel pistols need a piston, also called a booster or Nielsen device, to cycle with a can on. SilencerCo says on a Browning-style pistol “you need a piston” (source). Get the piston in your barrel’s thread pitch.

Can I shoot 5.56 through a .30 caliber suppressor?

Usually, if the maker rates the can for it. Dead Air says a 5.56 front cap is not required to shoot 5.56 through its 7.62 cans. Never do the reverse: “Be sure to NOT shoot 7.62 through a 5.56 front cap!” (Dead Air FAQ). Check the caliber list for your can.

Can I use a different brand mount on my suppressor?

Often, if the can has a common rear thread like HUB. Dead Air’s FAQ lists cans from SilencerCo, Energetic Armament, YHM and CGS that fit its KeyMo adapters. Using another brand’s mount may affect your warranty, so check with the can maker first.

Need a hand?

Not sure what your barrel’s thread pitch is or which mount fits your can? Contact us and tell us what you have. Shop all suppressors and parts. Suppressors ship to a licensed dealer near you, and our state shipping restrictions page lists where we cannot ship.

Sources

• SilencerCo, Mount Types Explained (January 16, 2026)
• Dead Air Silencers, KeyMo
• Dead Air Silencers FAQ
• ATF, Update to NFA transfer guidance

Change log

• October 26, 2026: First published.