View Full Version : How do you headspace a Mauser

July 04, 2008, 14:44
Was rooting around in the barn today and turned up a Mauser action. And, considering I have about 10 completed bolts and way more barrels than that--I may build one up. So, how do ya headspece one of these??

July 04, 2008, 15:32
Are you asking about checking, or reaming?

July 05, 2008, 09:43
A new or replacement barrel would be short-chambered by several .001"
After installing the barrel the chamber would be finished by reaming to correct headspace using the bolt supplied.

A used barrel is sometimes OK, but often has to be set back 1 full turn (depending on sights and markings) and the chamber reamed to correct length.

You might get lucky trying different bolts with the barrel installed.

July 05, 2008, 12:38
To properly install and headspace a Mauser barrel, you'll need make a couple different measurements with depth mic.

I'd recommend that you first check the barrel to make sure it'll torque up to the barrel properly. Do this by measuring the distance from the face of the receiver to the C ring inside the receiver. Write that measurement down. Then measure the distance from the breach face of the barrel to the primary torque shoulder. Write that down. You'll want those within a couple thousandths of each other to allow for crush when the barrel is installed.

Then, put a GO gauge in the chamber of the barrel and measure the distance from the torque shoulder on the barrel to the back of the GO gauge. Write that measurement down. Then, put the bolt in the receiver and measure the distance from the face of the receiver to the face of the bolt. Write that down. You want these measurements to be within a couple thousandths of each other. You can ream the chamber deeper or set the barrel back to get them in line with each other.

Once the barrel is torqued onto the receiver, clean the chamber, strip the bolt, and put the GO gauge back into the chamber. Then ease the bolt up to the GO gauge and see if you can close the bolt on it without forcing it closed. It closes without force, you're done. If the bolt won't close, you'll want to ream the chamber slightly deeper. Lastly, if the bolt closes really easily, you might want to check your headspace with a NO GO gauge and make sure the headspace isn't set too deep. Some guys like tight headspace and prefer their rifles to just close on GO. I prefer my rifles to close on GO but not close on NO GO which is a little bit looser headspace but allows me to shoot different brands of factory ammo without things getting real tight in the chamber.

One other comment on setting headspace on a Mauser is once you get everything measured, set up, and torqued together, don't change bolts. Mauser bolts are usually differ slightly from one to another and using a different bolt may change the headspace slightly.

July 05, 2008, 19:40


November 06, 2010, 11:03

Here is a blank drawing I made.
You might print it out, and fill in the dimensions of your project.

I do this for each Mauser barrel in my lathe.