How to cut and crown a rifle barrel and install a brake

Shorten a barrel and install a muzzle brake between centers on a lathe

April 7, 2014 Bill Marr Gunsmithing, Tutorial 0

I decided to cut the barrel back on my 24″ 308 Winchester to 22″ inches and install a brake.  Unlike most of the other brake and chamber work shown on this site, the majority of this installation will occur between centers, rather then through the headstock.  Lathes with a small spindle diameter, or short barrel sometimes require this technique.  In this case, the barrel is too short to install the brake through the headstock.

This Surefire MB762SSAL/RE muzzle brake is unique in the fact that it requires a 2.145″ long tenon, .775″ in diameter located behind the 5/8-24 thread required to mount the muzzle brake.  Cutting this tenon and the threads in one set up will ensure the everything is concentric to the bore.

I ordered the following items from Brownells:

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All lathe work was conducted on a Grizzly 4003G lathe.

Here is the business end of the customized Remington 700 rifle that we will be working on. Before handling the rifle, I ensure that it is safe and empty.
Here is the business end of the customized Remington 700 rifle that we will be working on. Before handling the rifle, I ensure that it is safe and empty.
Prior to removing the barrel from the action, I mark top dead center on a piece of masking tape.
Prior to removing the barrel from the action, I mark top dead center on a piece of masking tape.  I’ll need to know where this is in order to index the brake.
I secure the barrel in a vise and use an action wrench to remove the action.
I secure the barrel in a vise and use an action wrench to remove the action.
I'll be cutting the barrel back to 22". I mark the desired length on the barrel and cut on the waste side of the mark.
I’ll be cutting the barrel back to 22″. I mark the desired length on the barrel and cut on the waste side of the mark.
I mount the barrel through the head stock and square the edge after it is dialed in. Note: this could be donw with the chamber end secured in the headstock and the muzzle end supported by a steady rest.
I mount the barrel through the head stock and square the edge after it is dialed in. Note: this could be done with the chamber end secured in the headstock and the muzzle end supported by a steady rest.
I use a piloted, 60 degree center drill held in a floating reaming holder to ream an area on the muzzle end. This will allow the barrel to remain centered and supported on the live center in my lathe.
I use a piloted, 60 degree center drill held in a floating reaming holder to ream an area on the muzzle end. This will allow the barrel to remain centered and supported on the live center in my lathe.
Note how the live center's 60 degree nose is mates securely in the cut I made.
Note how the live center’s 60 degree nose is mated securely in the cut I made.
I am securing the chamber end in a four jaw chuck. I am using an old recoil lug to prevent the tenon shoulder from getting damaged.
I am securing the chamber end in a four-jaw chuck. I am using an old recoil lug to prevent the tenon shoulder from getting damaged.
The barrel set up between centers.
The barrel set up between centers.
I begin by cutting the tenon shoulder to .775" in diameter. I am using a high-speed steel right hand insert tool and Viper's Venom cutting oil.
I begin by cutting the tenon shoulder to .775″ in diameter. I am using a high-speed steel right hand insert tool and Viper’s Venom cutting oil.
The tenon turned to the proper diameter.
The tenon turned to the proper diameter.
I use a right hand 35 degree profile tool to cut the tenon for the threads. The standard right hand tool wouldn't clear the live center.
I use a right hand 35 degree profile tool to cut the tenon for the threads. The standard right hand tool wouldn’t clear the live center.
The tenon is coated in Dykem and lathe set up for threading. The muzzle brake requires 24 threads per inch.
The tenon is coated in Dykem and lathe set up for threading. The muzzle brake requires 24 threads per inch.
The threads are cut and a relief cut is made behind the threads before the tenon shoulder. This allows the brake to tighten against the shoulder.
The threads are cut and a relief cut is made behind the threads before the tenon shoulder. This allows the brake to tighten against the shoulder.
I screw the muzzle brake onto the barrel to check and adjust its timing.
I screw the muzzle brake onto the barrel to check and adjust its timing.
Since I had the lathe's live center in the muzzle, I need to cut a new crown. I set up the lathe's steady rest on the tenon I just cut. This allows me to protect the Cerakote finish on the barrel. I am using a #3 pilot .420 target crown tool secured in a Manson floating reamer holder to cut the crown.
Since I had the lathe’s live center in the muzzle, I need to cut a new crown. I set up the lathe’s steady rest on the tenon I just cut. This allows me to protect the Cerakote finish on the barrel. I am using a #3 pilot .420 target crown tool secured in a Manson floating reamer holder to cut the crown.
The new crown.
The new crown.
All done. The barrel is now 22" long and the brake is installed. I used the supplied thread locker for a secure installation.
All done. The barrel is now 22″ long and the brake is installed. I used the supplied thread locker for a secure installation.  Note: the exposed tenon behind the brake is supposed to be there.
It shoot well with the new brake. 10-rounds at 100 yards from 2 magazine fired off my pack.
It shot well with the new brake. 10-rounds at 100 yards from 2 magazines fired off my pack.
Top view of the brake installed.
Top view of the brake installed.

 

It may be louder with a brake, but it kicks less and looks much cooler!
It may be louder with a brake, but it kicks less and looks much cooler!

If you would like to see how this rifle was build, click here:  Building a Custom Remington 700 .308 Tactical Rifle

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