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Barrel Threading

Suppressor Thread Size: Common Barrel Thread Patterns

February 2, 2016 Posted by Silencer Central Team

From the invention of the first silencer to the present day, people have sometimes struggled to attach their silencers to their guns. While things were a bit easier in the days of the old Maxim silencer as there was really only one model to use, and just a couple thread pitches, we can no longer simply say ‘thread my barrel’ and expect the correct caliber silencer to fit.

No, instead we are faced with a host of different thread pitches, and a collection of adapters to allow fitting different silencers to different guns. While there are a few popular thread pitches that are close to “standard” due to military use, or common use on popular suppressor brands, expect that if you buy a gun with a factory threaded barrel, and a silencer, sometimes the two might not match up.

We’ve prepared a list of the thread pitches on many popular and common handguns and rifles. This factory-supplied data should help you in developing a collection of end caps and adapters to allow you to use your suppressor on as many different guns as possible. Unless otherwise stated, thread pitch is presented in inches with a right-hand thread pitch. Metric threading is listed as left-handed or right-handed metric (LHM, RHM).

Barrel Threading Common Questions.

What do the threading abbreviations mean?

These are more common for handguns, not rifles…

LH- Left Hand (as an example – M13.5×1 LH means the threads are backward from what you typically expect. This thread pitch would require righty-loosey, lefty-tighty…)
RH- Right Hand (as an example – M16x1RH means the threads work how you typically expect (righty-tighty…). If there is no LH or RH designation – RH is the default.)
M- Metric (for example – M13.5×1 LH means that the numbers are metric instead of standard.)
TPI – Threads per inch

Complete Thread Pitch Guide

Thread Pitch Guide for Handguns

Many handguns are now available with factory threaded barrels. In addition, after-market barrels provide some common threading options.

1911 Barrels

The venerable 1911 has long been a popular platform to build with custom barrels. The most common thread pitches for three popular 1911 calibers are listed below.

.38 Super – 1/2x28
9mm – 1/2x28
.45 ACP - .578x28

Aftermarket Barrels

Most aftermarket barrels for common handguns will use the following thread pitches. These are about as close to “standard” as you will get for barrels in common calibers. Aftermarket barrels can be purchased in metric threads as well.

.22 – 1/2x28
9mm – 1/2x28
.40 S&W – 9/16x24
10mm - 9/16x24
.45 ACP - .578x28

Thread Pitch Guide for Pistol Caliber Carbines

Pistol caliber carbines are increasingly popular due to their light weight, and the ever popular ability to use the same mags and ammo as a compatible handgun. Many carbines are made to accept common factory mags, or made to compliment a particular line of handguns. Widely used by law enforcement, for home defense and for some hunting, pistol caliber carbines build on the old cowboy tradition of keeping a lever action rifle and revolver in the same caliber for simplified logistics. Modern pistol caliber carbines are commonly suppressed, and here are the most popular models and their thread pitch.

Shop Pistol Silencers

Thread Pitch Guide for Rifles

From bolt action to semi-automatic sporting carbines, there are seemingly endless suppressor hosts out there in rifle form. These are some of the most popular and common rifle brands and thread pitches.

Common Pitch Range

.17 to below .243 - 1/2x28
.243 to .300 Win Mag - 5/8x24

Common Platforms

.223/5.56 (AR15) - 1/2x28
.30 Cal (AR10 etc.) - 5/8x24
300 BLK - 5/8x24
AK - M 14x1 LH
*350 Legend - 1/2x28
**450 Bushmaster - 5/8x32
458 SOCOM - 5/8x24

AR 15 Barrel Threads (and Other AR Styles)

This includes pretty much includes all AR-style rifles, carbines, and even pistols. Because AR muzzle threads are pretty much standardized due to industry or military standards, it’s a pretty safe bet your AR barrel has these threads in a given caliber. Naturally, all sorts of adapters and even muzzle brakes that fit silencers are available to make sure you can put your favorite silencer on your AR.

Big bore rounds like .458 SOCOM, .50 Beowulf, and other large-bore calibers may have thread pitches that vary from manufacturer to manufacturer. Consult with your rifle or barrel manufacturer for the thread pitch on your barrel.