View Full Version : TURKISH MAUSERS- By Harry Bonar

Bill Z
February 2, 2005, 08:47 AM
Posted on behalf of Harry Bonar


I have, as a personal experimental project, rebarrelled perhaps a dozen Turkish Mausers. I have not experienced any problems at all with these actions. However, there are certain steps which any Mauser Action should undergo in the process of converting them to sporting use. In a recent article, appearing on a web-site, a gentleman refers to the Turk.’ As a, “truck gun - a knock-about rifle.” The Turkish Mauser can be the foundation for a fine sporting rifle.

The 1938 Turkish Mauser has an extension on the front of the action, not a recessed bbl. seat, but an extension whose sole function is to hold the upper handguard in place. There are no threads in it and can be faced off to still have within a few thousandths the same ring length as the VZ24, or other large ring 98 actions. The bolt on the 38 Turkish is the same full length bolt as the VZ24 and other 98 actions. However, even though this is a large ring action the bbl. thread size is .980X12! (The regular 98 thread size is 1.100X12) I feel strongly that the supposed 11 ½ thread is a machining error. All of my experiments show a good 12 TPI. The Turk’ as it comes in military guise needs attention; some of these rifles I could have unscrewed the bbl’s. by hand, others required the bbl. vise and wrench.

First, let me make some initial remarks about action set back and hardness. I, feel, as P.O. Ackley does, that Rockwell, or other hardness tests on Mauser actions is worthless. Most all Mauser Actions of any vintage are made of low or medium carbon steel that doesn’t have enough “points” of carbon to harden homogeniously all the way through as do alloy steels. The outside of a Mauser action may exhibit a “C” hardness of 10, while the inner lug recesses, if the action is sectioned to test such, may be 40 to 45 on the “C” scale, and hardened to a depth of about .030! This is due to the fact that these actions are case hardened, or carburized, by induction, or other method. As you drill the action ring you will notice that the outside drills easily, but as you approach the inner surface your drill will “sing” and may break as it hits the inner hardened surface. This, in itself is a good sign of a properly treated action. The increased thickness of the ring, with the .980X12 thread actually makes this a stronger action than the 98 actions with the 1.100X12 thread size, all other things being equal.
“Set-Back” is a term gunsmiths use to denote the battering of the bolt, when fired, into the receiver lug recesses. If you feel a “bump” when closing any Mauser action steer clear. The Germans didn’t pay a great deal of attention to headspace since the case would be fired only once, or bolts getting switched in combat conditions. Rounds MUST chamber in combat. What happens, if the receiver is “soft” or if headspace is at “field guage” limit is that the firing pin drives the case forward,it goes off and the head comes back into contact with the recesses and slams into them again and again, producing “set back.” Many actions were soft, and exhibit this condition; if you find this in an action, junk it if it shows, upon removal of the bbl .this in the lug recess. A small bright spot can be dealt with but not massive lug battering! All bolt rifles, modern or old will show a slight “seat” as they are used initially; this is normal. You may not feel it but it is there and will not change during the life of the weapon if normal loads are used.

Let me clear up a great misconception about Mausers (98). The American loading for the 8X57JS is about 35,000 cup (copper units of pressure). The European loading is right up there with the 30-06 class; about 50,000 cup. There is a reason for this.
There are four variations of the 8X57.
a. the 8X57J---- bore dia. Is .318 (approx)
b. the 8X57 JS ------ bore dia. Is .323-324 (approx)
c. the 8X57JR------ rimmed version of the “J” bore
d. the 8X57JRS-------rimmed version of the “S” bore

Always have your military version headspace checked and evaluated before using European data in your “military Mauser” OF ANY MAKE OR YEAR.

Other than eliminating the extension of Turish Mausers these are my feelings on how to properly “sporterize” ANY Mauser action in the 98 class. Even the 93, the 94 and the 95 and 96 actions can benefit from certain aspects of these instructions.,

1. Unscrew bbl. and inspect inside of action; threads, recesses, etc. Clean up with carburetor cleaner, or gun blaster, and a bronze bristle brush, blow out with compressed air. Inspect lug recess as mentioned before.
2. Install a mandrell into bolt raceway in action and in a good lathe turn off the extension which is unthreaded and holds the handguard in place (Turk. only). Now just clean-up the very face of the action until even; no more that .004 to .010. At this juncture cut off the straight bolt handle according to Bolt Welding Jig instructions and mount on body in a good 3 jaw chuck and just barely “clean up” the face of bolt You will weld on a new handle later. You will find that the receiver ring length is just thousandths different from a VZ24 or other large ring action!
3. Inspect the bolt. The lugs, etc. Coat the bolt lugs (with the bolt striker assy. on) with lay out dye or cato marker, (all three lugs) and insert in action with trigger on and close bolt several times; this will tell you which lugs are touching. THE REAR SAFETY LUG SHOULD NOT TOUCH. If it does stone it till it doesn’t touch. Recheck front lugs, if only one does touch gently stone it back until BOTH front lugs start to touch. Then apply fine valve grinding compound to lugs and work bolt up a down about a dozen times (don’t take too much metal off of inner recess!) Both lugs should touch with a well defined area (about 60% to 75% contact) DO NOT HAVE REAR SAFETY LUG TOUCH! Remember a soft surface will lap a hard surface. I will tell you that ALL factory rifles will benefit from this, IF, you are fitting a new bbl. Very few factory rifles bear evenly on both lugs!
4. Now, you have an action with a true face, a bolt bearing on both lugs and a true bolt face all lined up - a great secret to the beginning of accuracy.
Now, you are ready to take your action measurements. Strip bolt and insert into action held vertically in vise. With depth micrometer, measure down to the bolt face from the action face. Record that measurement. Now measure down to the inner bbl. seat and if you find unevenness record the least measurement; if it is even then fit the bbl. to both shoulders. You want the bbl. to fit to a true surface, and if the measurement is even fit to BOTH shoulders. The tenon of the bbl. should either seat to both shoulders, or, if the measurement shows unevenness, have no more than .001 space from the inner recess. This will assure the bbl. is seated to a true surface, viz., the action face. This is no different from the Rem. 700, the Win. 70, the Howa or most modern bolt rifles. Barrels do not need a ten foot wrench and a 500 pound gorilla on it to seat a bbl. Come up on the shoulder several times, be sure of your seating and then seat it home soundly. After all this test fire with a FACTORY round; you do not need a proof load; do not try to load one - you do not know what pressures you’re getting! Fire four or five rounds. Check bolt closure for set back, run your headspace guage again and if it’s O.K. stock it!

Thank you for bearing with me; this is how I do it, I take no responsibility for these instructions to the general public, or how you do it. These are suggestions, nothing more.
Harry Bonar. Harry’s Gun Shop 4625 Veto Rd. Rt, 1 Vincent, Ohio 45784

Posted on behalf of Harry Bonar

February 3, 2005, 07:44 AM
im gonna get one of these in about a week.. can you post pics cuzz im pretty much a dumb ass and will mess it up. thanks :D

Bill Z
February 3, 2005, 08:46 AM
Harry, if you've got 'em and can't post 'em, shoot them my way and I'll get them up for you.

Harry Bonar
February 4, 2005, 11:12 AM
Dear BILL Z:
Thank you so much for helping; looks great and I'll try my best to get pictures. I really enjoy being part of the FORUM with all you great guys!
Again: thanks for the help and I hope this will help someone. Doing this is really not too hard and most anyone can do it right the first time. It is only after many of my own mistakes that this was put together.
I feel a responsibility to be as much as a help to other gunsmiths, not to brandish a big ego. I see that the Forum is also free and helpful with info and the "smiths" are eager to help.