What the suppressor is rated to handle
Caliber rating concerns the cartridge/projectile and the suppressor manufacturer's approved use. It does not tell you the barrel thread.
APS suppressor education
Suppressor Thread Pitch
& Fit Guide
Will this suppressor fit my firearm?
Start by separating three different questions: caliber, barrel thread, and suppressor mounting system. A matching thread alone does not establish complete compatibility.
The fit equation
Thread pitch is only one part of fit.
A customer can have the right caliber but the wrong barrel thread. A barrel can have the right thread but still require a different suppressor mount. A suppressor can use a common rear interface such as HUB while the barrel itself uses a completely different thread.
The exact firearm and barrel specification wins over a generic caliber assumption. When a manufacturer publishes a specific thread pitch or mounting requirement for your exact model, use that information.
How the barrel or muzzle device attaches
Examples include 1/2×28, 5/8×24 and metric patterns. The thread must match the direct-thread adapter, piston, or muzzle device being used.
How the suppressor connects to the firearm
Depending on the product, this can be direct-thread, a pistol piston/booster assembly, or a quick-detach muzzle-device system.
Find your thread pitch
Use the strongest source first.
Do not infer thread pitch from caliber alone. Many calibers appear with more than one thread pattern across manufacturers, models and aftermarket barrels.
Check the exact manufacturer specification
Use the firearm manufacturer's specification for the exact model and barrel. For an aftermarket barrel, use the barrel manufacturer's specification instead.
Check barrel or product markings
Some threaded barrels, adapters and muzzle devices are marked with the thread pattern. Match the marking to the manufacturer's documentation when possible.
Measure only when the specification is unclear
A caliper and thread-pitch gauge can help confirm nominal diameter and pitch. If you are not certain, APS or a qualified gunsmith can verify the thread before you purchase a mount.
Common thread examples
Patterns you will see often.
These are common examples, not universal standards. Exact barrel specifications can differ even within the same caliber family.
| Thread pattern | Often seen on | What the notation means |
|---|---|---|
| 1/2×28 | Many .22 LR, .223/5.56 and 9mm threaded barrels | About 1/2-inch nominal diameter, 28 threads per inch |
| 5/8×24 | Many .30-caliber rifle barrels, including common .308 and .300 BLK configurations | About 5/8-inch nominal diameter, 24 threads per inch |
| .578×28 | Many .45 ACP threaded pistol barrels | .578-inch nominal diameter, 28 threads per inch |
| M13.5×1 LH | Some European-pattern 9mm barrels | 13.5 mm nominal diameter, 1 mm pitch, left-hand thread |
| 14×1 LH | Common on a number of AK-pattern barrels | 14 mm nominal diameter, 1 mm pitch, left-hand thread |
Do not force mismatched threads.If a mount does not start cleanly and correctly, stop and verify the barrel and mount specifications.
Mounting systems
Barrel thread ≠ suppressor mount.
Understanding the mounting system prevents one of the most common compatibility mistakes.
Barrel thread → suppressor adapter
The suppressor or its direct-thread adapter must match the barrel thread specified by the firearm or barrel manufacturer.
Common on many centerfire pistols
Many tilting-barrel pistols use a piston/booster system. The piston thread must match the pistol barrel, and the suppressor manufacturer must approve that configuration.
Barrel thread → muzzle device → suppressor
The muzzle device matches the barrel thread, while the suppressor locks to that manufacturer's compatible mounting interface.
Usually the suppressor's rear interface
HUB commonly refers to the suppressor-side mounting interface. It is not normally the thread specification on the firearm's barrel.
Pistols, rifles & shotguns
Different platforms can use different fit logic.
Rifles: direct-thread and muzzle-device/QD systems are common. Confirm barrel thread, suppressor caliber rating, mount compatibility and the manufacturer's barrel-length or configuration requirements.
Pistols: many centerfire semi-automatic pistols use a piston/booster system. The piston itself must match the barrel thread.
Shotguns: suppressor systems can use manufacturer-specific mounts, including systems that interface with internal choke threads. The shotgun model, choke-thread family and suppressor mount must all be confirmed.
1Firearm manufacturer
2Exact model
3Caliber
4Factory or aftermarket barrel
5Published thread pitch / markings
6Suppressor + mount you are considering
Send APS these details—and photos of barrel or adapter markings when useful—if you want help confirming the correct mount path.
Suppressor fit FAQ
Questions buyers ask before ordering.
Use these answers as a starting point. The exact manufacturer specifications still control.
What does 1/2×28 mean on a threaded barrel?
It is an imperial thread pattern: about one-half inch nominal major diameter with 28 threads per inch. Confirm the exact barrel specification before choosing a mount.
Is 5/8×24 the standard thread for every .30-caliber rifle?
No. It is common on many .30-caliber rifles, but caliber does not guarantee thread pitch. The exact firearm and barrel specification controls.
Is HUB 1.375×24 the same thing as barrel thread pitch?
No. HUB commonly describes the suppressor rear mounting interface. The barrel thread, muzzle device and suppressor mounting interface are separate compatibility points.
How do I find my barrel thread pitch?
Start with the firearm or barrel manufacturer's exact specification and any barrel markings. If those are unclear, measure with the correct tools or have APS or a qualified gunsmith confirm it.
Does matching the thread pitch mean a suppressor is safe to use?
No. Thread or mount compatibility is only one part of fit. Caliber rating, mounting-system requirements, alignment and the suppressor manufacturer's instructions also matter.
Still not certain?
Send APS the exact firearm details.
Manufacturer, model, caliber, factory or aftermarket barrel, any thread markings, and the suppressor you are considering.