HexCore Mounts — Suppressor & Muzzle Reference
Thread Pitch &
Muzzle Device Reference
Common barrel thread pitches by caliber, muzzle device types, and suppressor mounting systems explained. Know your threads before buying a muzzle device, suppressor mount, or barrel — the wrong thread pitch means nothing fits.
Thread Pitch by Caliber
Muzzle Device Types
Suppressor Mounts
10 FAQs
12+
Thread Pitches
5
Device Types
8
Mount Systems
10
FAQs
Common Thread Pitches by Caliber
Barrel thread pitch determines what muzzle devices and suppressor mounts can be attached. Using the wrong thread pitch will not fit or — worse — will cross-thread and damage the barrel. Always verify your barrel's thread pitch before purchasing any muzzle device.
| Thread Pitch | Standard For | Common Calibers | Notes |
|---|---|---|---|
| 1/2×28 TPI | Standard .22-cal / 9mm | .223 Rem, 5.56 NATO, .22 LR, 9mm, .300 BLK, 5.7×28mm | The most common thread pitch in the U.S. market; standard on AR-15 barrels and most 9mm pistols |
| 5/8×24 TPI | Standard .30-cal+ | .308 Win, 7.62 NATO, 6.5 Creedmoor, .300 Win Mag, .300 PRC, .350 Legend | Standard on AR-10 barrels, bolt rifles in .30-cal+, and most 6.5mm+ calibers |
| M13.5×1 LH | European 9mm pistol | 9mm (HK, SIG European, Beretta, Walther) | Left-hand thread (reverse from U.S. standard); common on European-made 9mm pistols; requires adapter for 1/2×28 devices |
| M14×1 LH | AK-pattern / 7.62×39 | 7.62×39, 5.45×39 (some) | Left-hand thread; standard on most AK-47/AKM barrels; 14mm LH adapters widely available |
| M15×1 RH | HK 7.62 / large rifle | .308 Win (HK platforms) | Right-hand metric; found on HK91/G3 pattern rifles and some European .30-cal |
| M16×1 LH | AK-74 / 5.45 | 5.45×39 | Standard on AK-74 platform barrels |
| .578×28 TPI | .45 ACP pistol / .45-70 | .45 ACP, .45 Colt, .458 SOCOM, .45-70 Gov | The .45-cal equivalent of 5/8×24; standard on .45-cal threaded barrels |
| 9/16×24 TPI | Some .375 / 10mm | .375 Raptor, 10mm, .40 S&W | Less common; found on some 10mm barrels and specialty calibers |
| 3/4×24 TPI | .50 BMG / large bore | .50 BMG, .458 SOCOM (some) | Large-bore thread pitch for .50-cal and some specialty big-bore applications |
| M18×1 | Shotgun (some) | 12 Gauge (some models) | Found on select threaded shotgun barrels; less standardized than rifle/pistol threads |
| 3-Lug | 9mm subgun / PCC | 9mm (HK MP5-pattern, SP5, clones) | Not a thread — a tri-lug mount system. Quick-attach without threading; common on MP5-style hosts and compatible suppressors |
| Choke Thread | Shotgun | 12 Gauge, 20 Gauge | Shotgun suppressors typically attach via the choke thread system (Remington, Benelli, Beretta pattern varies) |
Left-hand vs right-hand threading: AK-pattern barrels (M14×1 LH, M16×1 LH) and many European pistols (M13.5×1 LH) use left-hand threads. U.S.-standard muzzle devices (1/2×28, 5/8×24) are right-hand. Cross-threading a left-hand barrel with a right-hand device will damage the barrel. Always verify thread direction.
Muzzle Device Types
| Device Type | What It Does | Pros | Cons | Suppressor Note |
|---|---|---|---|---|
| Flash Hider | Disperses unburnt propellant gas to reduce visible muzzle flash | Reduces shooter flash blindness in low light; standard military configuration (A2 birdcage) | Minimal recoil reduction; marginal concussion reduction | Many suppressors mount directly over specific flash hider patterns (SureFire SF3P, Dead Air FH) |
| Muzzle Brake | Redirects gas rearward/sideways through ports to reduce felt recoil | Significant recoil reduction (up to 50%+); faster target re-acquisition | Increased blast, concussion, and noise to sides and rear; unpleasant for bystanders and adjacent shooters | Many QD suppressors mount over a specific muzzle brake (SureFire SOCOM, Dead Air KeyMicro, SilencerCo ASR) |
| Compensator | Ports gas upward to reduce muzzle rise | Keeps muzzle flat for fast follow-up shots; common in competition | Increased downward blast; may increase felt recoil impulse; loud | Some comp-style devices serve as suppressor mounts (Griffin Taper-Lok Comp) |
| Blast Forwarding Device | Directs blast and concussion forward, away from the shooter | Reduces concussion at the shooter's position (short barrels, indoor ranges) | Does not reduce recoil; increases forward blast signature; no suppression | Not a suppressor mount; used when a suppressor is not available but blast mitigation is needed (KVP Linear Comp, Strike Industries Cookie Cutter) |
| Thread Protector | Covers exposed barrel threads when no device is mounted | Protects threads from damage, debris, and corrosion | No functional muzzle effect | Remove before mounting any device; comes factory-installed on most threaded barrels |
SureFireDead AirSilencerCoHUXWRXGriffin ArmamentRugged SuppressorsYHMAero PrecisionBCMVG6Precision ArmamentStrike Industries
Suppressor Mounting Systems
| Mount System | Manufacturer | Type | Requires | Notes |
|---|---|---|---|---|
| Direct Thread | Universal | Screw-on | Matching thread pitch (1/2×28 or 5/8×24 typical) | Simplest system; lightest; no mount device needed; slower to attach/detach; slight POI shift on removal/reattach |
| SureFire SOCOM / Fast-Attach | SureFire | QD ratchet | SureFire SF3P, SF4P, SOCOM brake, or Warcomp | Military standard (SOCOM contract); proven; heavy; compatible across all SureFire SOCOM cans |
| Dead Air KeyMicro / Xeno | Dead Air Silencers | QD | KeyMicro brake/FH or Xeno adapter | KeyMicro is proprietary Dead Air QD; Xeno is an open-standard system designed to be cross-compatible |
| SilencerCo ASR / Charlie | SilencerCo | QD ratchet | ASR or Charlie brake/flash hider | ASR is the legacy system; Charlie is the newer, more robust mount; not cross-compatible |
| Griffin Taper-Lok / SDPM | Griffin Armament | Taper mount + lock ring | Griffin Taper-Lok or SDPM muzzle device | Taper fit provides excellent concentricity; SDPM is a short direct-pull mount for minimal added length |
| Rugged Anchor Brake | Rugged Suppressors | QD | Rugged Anchor Brake | Simple one-piece mount; the brake serves as the suppressor adapter |
| HUXWRX QD | HUXWRX Safety Co. | QD flow-through | HUXWRX flash hider / muzzle device | Designed for the Flow series; QD attachment with flow-through gas management |
| YHM Phantom QD | Yankee Hill Machine | QD | YHM Phantom flash hider or brake | Budget-friendly QD system; compatible across YHM Turbo, Resonator, Nitro lines |
Mount choice matters for suppressor buyers: Before buying a suppressor, decide which mounting system you want to use across your firearms. Buying multiple muzzle devices in the same QD system lets you move one suppressor between hosts quickly. SureFire, Dead Air Xeno, and YHM Phantom are the most common multi-host QD ecosystems.
Pin-and-Weld — Permanent Attachment for NFA Compliance
A pin-and-weld permanently attaches a muzzle device to the barrel so the combination counts as a single unit for measuring overall barrel length. This is most commonly done on 14.5" barrels with a ~1.5" muzzle device to reach the 16" minimum for non-NFA rifle status (or 13.7" + longer device).
- The device must be permanently attached — pinned through the barrel shoulder and welded over
- Removing a pin-and-weld device requires a gunsmith (drilling, grinding, or milling)
- Plan your suppressor mount BEFORE pin-and-weld — you are locked into that muzzle device
- Common pin-and-weld lengths: 14.5" + 1.5" device = 16", or 13.7" + 2.3" device = 16"
- The 13.7" barrel + longer muzzle device trend is growing because it produces a shorter overall package while still meeting 16"
- With the $0 NFA stamp (P.L. 119-21, effective January 1, 2026), SBR registration is now more accessible — consider whether pin-and-weld or SBR registration better fits your needs
Timing & Shims
Some muzzle devices (brakes, flash hiders with directional ports) must be "timed" — rotated to the correct orientation so ports face the right direction. Since thread engagement varies by barrel, shim kits or peel washers are used to time the device without under- or over-torquing.
Method
Shim Kit
Stack thin steel shims of varying thickness behind the device until hand-tightening lands the ports at the correct orientation. Then torque to spec. Most suppressor muzzle device manufacturers include a shim kit.
Method
Peel Washer / Crush Washer
Crush washers compress as the device is torqued, allowing the device to be timed to the correct position. Simpler than shims but less precise. Generally NOT recommended for suppressor mount devices — use shims for QD muzzle devices.
Suppressor concentricity: A poorly-timed or improperly-shimmed muzzle device can cause the suppressor to sit off-axis from the bore. This is a baffle strike risk — the bullet can clip an internal baffle, destroying the suppressor and potentially injuring the shooter. Always verify alignment with a rod or alignment tool after mounting.
Frequently Asked Questions
How do I know what thread pitch my barrel has?▾
Check the barrel manufacturer's specifications. If unknown, use a thread pitch gauge (available for under $10) or measure the thread diameter and count threads per inch. For most U.S.-market AR-15 barrels in .223/5.56/9mm/.300 BLK, it's 1/2×28. For .30-cal+ (AR-10, bolt rifle), it's usually 5/8×24. European pistols often use M13.5×1 LH.
Can I use a 5/8×24 device on a 1/2×28 barrel?▾
No. The thread pitches are physically different and incompatible. Attempting to force a mismatched device will cross-thread and damage the barrel. Thread adapters exist (1/2×28 to 5/8×24 and vice versa) but add length and can affect concentricity — they should be considered a compromise, not a preferred solution.
Flash hider or brake — which is better for a suppressor host?▾
For a suppressor QD mount: whichever your suppressor manufacturer recommends. Many QD systems offer both a flash hider and a brake version as the suppressor adapter — the suppressor mounts on either one identically. Flash hiders are quieter and less concussive when shooting unsuppressed. Brakes reduce recoil but are very loud without the can. For a dedicated suppressor host, many shooters prefer the flash hider version for the days the can comes off.
What is a baffle strike and how do I prevent it?▾
A baffle strike occurs when the bullet contacts an internal baffle inside the suppressor instead of passing cleanly through the bore. Causes include poor suppressor alignment (bad timing/shimming), a damaged barrel crown, a concentric bore issue, or using a suppressor rated for a larger caliber with a smaller bore opening. Prevention: always verify alignment with a rod or alignment tool, ensure proper muzzle device timing with shims, and never use a suppressor on a caliber it's not rated for.
Should I use a crush washer or shim kit?▾
For a standard flash hider or brake (no suppressor): a crush washer is fine and simple. For a suppressor mount / QD muzzle device: always use a shim kit. Crush washers can allow the device to rotate under suppressor weight or thermal cycling, and they don't provide the repeatable concentricity that shims do. Most suppressor mount manufacturers include a shim kit.
What is the Dead Air Xeno system?▾
Xeno is Dead Air's open-standard mounting interface. Unlike the proprietary KeyMicro system, Xeno adapters are designed to work with multiple suppressor brands (with compatible adapters). The Xeno adapter threads directly onto 1/2×28 or 5/8×24 barrels and provides a standardized QD interface. It's becoming one of the most popular multi-host suppressor mounting solutions.
Can I direct-thread a QD suppressor?▾
Many QD suppressors also accept a direct-thread adapter as an alternative to the QD mount. This is useful on hosts where you want the shortest possible overall length or don't need quick-detach capability (e.g., a dedicated bolt rifle). Check your suppressor manufacturer's adapter options.
What about 3-lug mounts?▾
The 3-lug mount is a quick-attach system originally from the HK MP5 platform. Three lugs on the barrel index into matching cuts on the suppressor, locking with a quarter-turn. It's the fastest suppressor mount type. Available as a barrel adapter for AR-pattern 9mm PCCs and some pistol-caliber hosts. Dead Air Wolfman, SilencerCo Omega 36M, and others support 3-lug adapters.
Is a thread protector necessary?▾
If you don't have a muzzle device installed, yes. Exposed barrel threads will get damaged by impact, debris, and corrosion. Damaged threads can make it impossible to mount a muzzle device or suppressor later. Thread protectors are cheap ($5–15) and come standard on most threaded barrels.
Does the $0 NFA stamp change how I should think about muzzle devices?▾
Yes — in two ways. First, suppressors are more accessible with the $0 stamp (P.L. 119-21, effective January 1, 2026), so choosing a muzzle device that doubles as a QD suppressor mount is now more practical. Second, SBR registration is also $0, which means pin-and-weld on 14.5" barrels is no longer the only path to a non-NFA rifle — you can SBR the lower and run any barrel length with a removable muzzle device.
