Mauser Rebarrel - Part 1, Fitting

[Clemson]

Continuing the Model 48 rebarrel project, this series focuses on how the barrel is fitted to the action. The action in this case is a Model 48 Yugo Mauser. The barrel is from Midway, and today it would probably be called an Adams & Bennet F14 in .257 Roberts. I say "today" because this particular barrel came was bought several years ago before Midway started calling them A&B. This one is a 21" light sporter contour, and it is short-chambered.

 

Once disclaimer is in order -- This is NOT the only way to do this rebarrel job. It is the way that I chose to do this particular job. My only intent is to show how it can be done. I don't claim that my method is better than any other.

 

Remember that we squared the torque shoulders in this thread: http://www.sporterizing.com/index.php?showtopic=4287

 

Lets start by measuring the distance from the secondary torque shoulder to the primary torque shoulder and to the bolt face. Record these measurements.

 

Measure the tenon on the barrel to see how much you will have to adjust the shoulders:

 

The barrel is set up with the muzzle in a collet and with a live center in the breech. The Safety Breech is a boss that is cut into the rear of the barrel around the chamber. It makes the barrel fit deeper into the "C" ring by the depth of the boss.

 

I cut the boss to depth, then I trimmed it to the proper diameter using a parting tool. Note the caliper: I use a decidedly low-tech approach here. I set the caliper to the diameter of the boss on the takeoff military barrel. I cut the boss down until the caliper slides on.

 

The secondary torque shoulder is cut forward until the dimension matches the measurement that we took in the first step plus about 1 1/2 thousandths. The bearing needs to be on the primary (inner) shoulder. That outer shoulder has too little bearing area. Assuming about 0.002" of crush, both shoulders will bear, but the primary work will be done by the primary shoulder.

 

The resulting "Safety Breech" encloses the cartridge head. We will cut an extractor slot after chambering.

Clemson

[donmarkey]

Great show! Keep it up.

-Don