Muzzle Brake Thread Size: Barrel Threading Explained

Love the idea of adding a muzzle brake to your favorite rifle but aren’t sure whether your top picks are a match for your barrel? Don’t worry, you aren’t alone. But figuring out your barrel thread size isn’t difficult, and it is important to match any barrel device to your muzzle for a secure, safe fit. 

Take a look at what barrel threading you are most likely dealing with and how to match your muzzle brake with a specific caliber rifle. We explain the threading types and terminology and a guide to the most popular rifles out there. 

What is Barrel Threading?

Barrel threading refers to the threads located at the end of your muzzle to accept various muzzle devices. Muzzle devices, such as muzzle brakescompensators, and suppressors have a thread that screws onto your muzzle. These tighten down for security to avoid becoming loose when firing

It is important to purchase products with the same threading measurements as your barrel to ensure a proper fit. Some muzzle devices can work with an adaptor, but you still need to ensure your barrel and device are designed for the caliber size you are shooting. 

Threading Measurements Explained

In order to understand how to match up your muzzle and muzzle device, you need to first understand the measurements of each. 

US-made devices are threaded using standard US measurements and are labeled as Threads Per Inch (TPI). This is a measurement of how many threads are found within an inch of length. 

Firearm barrel with threading

Foreign devices are threaded to Metric specifications and are measured in pitch or the distance between adjacent threads. Metric device measurements will be preceded with the capital M to indicate the pitch distance and avoid confusing them with standard measurements. 

The measurements will also be followed with an LH or RH to indicate Left-Hand threading or Right-Hand threading respectively. If no threading direction is indicated, it defaults to Right-Hand. Most devices are RH and follows the old saying: righty tighty, lefty loosey.

Muzzle Brake Threading Guide

Different caliber cartridges require different barrel sizes, and thus different thread measurements. If you are thinking of adding a muzzle brake, or any other muzzle device to your rifle, keep the following chart in mind. 

Of course, this is just a general chart and differing manufacturers may have a different thread pitch or even a proprietary thread to match their products. But, this gives you a general idea of the most popular thread sizes to match with the proper caliber weapon. 

Barrel Thread

Application

Caliber

1/2-28 RH

AR-15, M-16, AR-180

Most .223/5.56

Most .22s

.223/5.56

.223/5.56

.22

1/2-36 RH

AR-15, M-16, AR-180

9mm

9/16-24 RH

AR Grendel

6.5mm

5/8-24 RH

AR10/M14

Most .308

Most .30

300 Blackout

AR-10

.308 CAL

.308 CAL

.30 CAL

.300 CAL

7.62 x 39 / 6.8 SPC

11/16×24 RH

.450 Bushmaster

Some .308

.450

.308

1″ x 14 RH

AR450

0.50 BMG

Barrel Thread

1/2-28 RH

Application

AR-15, M-16, AR-180

Most .223/5.56

Most .22s

Caliber

.223/5.56

.223/5.56

.22

Barrel Thread

1/2-36 RH

Application

AR-15, M-16, AR-180

Caliber

9mm

Barrel Thread

9/16-24 RH

Application

AR Grendel

Caliber

6.5mm

Barrel Thread

5/8-24 RH

Application

AR10/M14

Most .308

Most .30

300 Blackout

AR-10

Caliber

.308 CAL

.308 CAL

.30 CAL

.300 CAL

7.62 x 39 / 6.8 SPC

Barrel Thread

11/16×24 RH

Application

.450 Bushmaster

Some .308

Caliber

.450

.308

Barrel Thread

1″ x 14 RH

Application

AR450

Caliber

0.50 BMG

What If a Barrel Isn’t Threaded?

If a barrel isn’t threaded, no worries. Sometimes older or specialty barrels have not been threaded, but that doesn’t mean you cannot use them with a muzzle brake or other muzzle device. A gunsmith can easily thread a barrel to your device specifications without issue. This is also true if you purchase a device that fits your caliber, but has a specialized or odd threading measurement.  

Muzzle Brakes and Other Muzzle Devices

Close up Muzzle break on sand

Muzzle brakes are an excellent way to help reduce felt recoil and muzzle lift for a more controlled shooting experience. Compensators work much in the same manner, providing excellent stability and kickback reduction. 

Suppressors work to reduce noise, but also provide barrel stability and reduced forces as well. 

All are great ways to modify your rifle in a simple, DIY manner, but only if you have the correctly fit device for your host thread and a tight fit to get the most out of your addition. 

Wrapping It Up

Muzzle devices require a matching host thread on your barrel in order to provide a secure fit. Muzzle devices also must match your firearm caliber. Almost all devices are easy to secure on your own, but if you have any concerns or know there are some threading inconsistencies, a gunsmith can do this for you. 

Let us know if you have any questions below, and, as always, please share!