In this article we will show the steps to installing a muzzle brake.
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Ok. Let’s install a muzzle brake!
The muzzle brake I will be installing is a Shrewd brand muzzle brake threaded to a thread pitch of 1/2″x28tpi. The first step to do is turn the barrel down to .500 diameter. This diameter extends back from the muzzle end of the barrel 1/2″. This particular muzzle brake requires a thread relief to be machined for the brake to install correctly.
Once the major diameter of the portion to be threading has been achieved and the thread relief cut, the next step is to prepare to cut the 1/2x28tpi threads. Dykem layout fluid (blue in this case) is brushed onto the portion of the muzzle to be threaded.
While the Dykem is drying I sharpen the lathe bit that will be used to cut the threads. I use a 1/4″ Carbide tooling blank to create my own thread cutting tools. This blank has been ground to cut a 60 degree thread. It is honed by hand each time before use to ensure the bit is as sharp as possible to cut the best threads.
Next, I will setup my Grizzly Gunsmith Lathe to cut the threads. The sharpened tool bit is installed with the crossfeed of the lathe set to 29.5 degrees. The bit is squared to the work using a 60 degree threading gauge.
The Grizzly Gunsmith Lathe is setup to cut 28tpi threads. A trial pass is made and checked using a thread pitch gauge.
Multiple passes are made on the lathe to cut the threads to proper depth. As the threads are getting close to finished dimensions, the brake is used to check the progress until it fits.
The next step to installing a muzzle brake is to blend the brake to the diameter of the barrel. Different barrel contours require different diameter brakes. In this case, the Shrewd brake is bigger than the barrel diameter so it will need to be reduced on the back side of the brake to blend in with the barrel. This is accomplished with the use of a file.
The file marks are removed with sandpaper. Starting with 240grit, we work up progressively to 320 grit, 400 grit, and finish with 600 grit.
When installing a muzzle brake, the final step is to ensure that the hole in the brake is opened to .020 above the bullet diameter. This is accomplished using the correct sized drill bit.
The only steps left for installing a muzzle brake is to deburr the hole just drilled and blue the brake with either cold blue, rust blue, or a spray like Duracoat or Cerrakote. This brake was rust blued to closely match the barrel finish. Unfortunately, I forgot to take a picture of the final product!
While installing a muzzle brake is not rocket science, proper machine work by a competent gunsmith with the proper tools to do the job correctly will ensure satisfactory results.