Updated October 6, 1999
Mauser Action Tune up.
By Fred Melzer
The Mauser 98 action is easy to accurize with ordinary hand tools. Here are a few tips that will make your Mauser hunting rifle a super shooter.
1.) Glass-bed the action and two inches of barrel ahead of the receiver. Epoxy two hardened steel studs about 2.25" long, between the magazine box on each side. Mix a little ground up fiber glass with the epoxy glue for high compressive strength. The two studs are fitted to make solid contact with the recoil lug on each side and flush under the action. Two, approx. 7/32", high speed drills cut to size work fine. Grooves in the wood should not be too big. Rough up the studs with file notches. The two studs are glued in after the glass bedding and with the magazine box in place. There are other ways of increasing the recoil lug area, but not with ordinary hand tools.
Glass bedding is done without the use of action guard screws. The barreled action is set on three very small wood-screws, two behind the recoil lug and one under the tang. The action is held in place with tape and the front of the barrel is supported with play dough. Use headless inletting screws for line up. No stress is wanted. Make sure the action is square with the screw holes so the screws won't bind later.
A second thin glass bedding job is recommended to take up any shrinkage that may occur, due to various bedding thickness. Make certain the recoil lug stud is not bottoming out in the floor plate recess. A minimum of 3/32" glass bedding in the recoil lug area should be used, more along the sides and bottom. All areas should be slightly undercut to lock the glass bedding in place. Drill two rows of 1/8" holes about a 1/4 deep radial 45 degrees in the 2" barrel area to lock that part of the glass bedding in place in front of the action.
I make my own glass bedding material from marine polyester resin and ground up rigid fiber glass roof insulation. Use STP sparely for release agent. Coloring is done with Lamb Black or Bismarck Brown powder or liquid resin color for marine use. All this material is cheaply available in most paint and hardware stores anywhere or shops that do fiber glass work.
This mix is very hard and has high steel like compressive strength. Tensile strength is enormous. The resin has to be thickened with ground fiber glass to the consistency of thick molasses. The wood is first coated or primed with a Q-tip with unmixed resin and catalyst for good bonding. All wood needs covering with masking tape, and holes filled with play dough or foam. Some of this stuff melts with resin, best to test it. Magazine well is filled with a tightly fitted card board. Remove the trigger.
The barrel action is removed as soon as the resin is set up, but still a little soft. A sample of left over mix on your bench will tell you when. The tricky part is not to rip the glass bedding loose or freeze the metal parts in the wood stock. The three small wood screws are sunk down a halve turn. After clean up and oiling the barreled action the gun is put together, the floor plate is installed and the screws snugged up tight, but not real tight. This will compress the glass bedding. A few wraps with a wooden hammer in the center of the action will relieve bending stresses. Leave set over night.
2.) Free float the barrel. Some barrels like 8 lbs. uplift on the fore arm tip with the rest free floated.
3.) Reduce the recoil stud diameter a little, so the floor plate stud is not taking any recoil.
4.) Bed the rear tang without putting any downward pressure on it. The wood at the back of the tang has to be relieved 1/32" with a Dremel tool or a wood gouge.
5.) Drill out the rear screw hole and install a steel sleeve to fit the guard screw. Epoxy the sleeve in place 0.002 below the tang bottom. Roughen up the hole in the wood and the outside of the sleeve with grooves. Mix a little ground up fiber glass with the epoxy glue for high compressive strength. Hold the barrel action in place with tightly wrapped masking tape. Use the rear guard screw to hold the sleeve in line without the floor plate. An in letting stud screws works best for this. Coat your screw with STP for release.
6.) The military trigger can be tuned to single stage to 2.5 lbs. with careful stoning. But an adjustable trigger is the way to go. A Canyar double set trigger is a good one; it can also be used as a fine single stage trigger. The above will usually make a Mauser shoot very well with good precision hand loads.
A 22-250 shot under a halve inch group with a Douglas barrel using these modifications. And an 8x57 shot 5/8" with a mint military barrel. Many others I have done did as well. Very few fancy factory hunting rifles are anywhere near as good.
You can also have the action trued and the recoil lugs seated to 100% contact. You should check that the 3rd rear lug has a few thousands clearance. This is a safety lug only and should not take ordinary recoil the same goes for the bolt handle. The bolt can be sleeved for less play. This is a precision machining job. A short stroke speed lock, Buehler wing safety, or an after market cocking piece would complete the job very nicely. And of course you need to modify the bolt handle for scope use and drill and tap the receiver for scope bases. On closing I like to say that good 98 Mausers are not easy to get anymore.
Here are some added comments.
By Ted Penrod.
Fred the Reloader:
Read your article re Accurizing the 98 Mauser with interest and I agree with everything you say. Also, I would like to add a couple of things that you may or may not do or have done to the stock 98 action. I too like to work on the military trigger but short of replacing it. You can drill and tap the bottom of the floor plate. Then install a small metal block and block off the military two-stage trigger. Producing a trigger that is much more user friendly and comparable to a civilian trigger job. I have placed this modification on my rifles and it has worked very well for me. Also, if you perform the work you have stated and find the rifle still doesn't shoot as well as expected the next step may well be re-barreling. But first, you should inspect the muzzle crown and the bore and see if you have "dings' in the muzzle. I took a 98 in 8x57 that refused to tighten up smaller than about five inches. I cut the barrel back to 22" and recrowned the muzzle, nothing more. I had already worked on the trigger; the safety and glass bedded the action into a Bishop stock blank. First time on the bench with Remington factory loads and we were down to about two inches. With some more tuning on the ammo and carefully working up a load the little rifle likes, I believe it will shoot a 1 1/2, maybe would get on down to an inch. This is not bad accuracy for a light woods rifle with a military barrel. Like you said, a lot of folks are hunting with commercial rifles that absolutely will not shoot this well.
Again, enjoyed your article and your website. Keep up the good work. Shoot
safe, shoot carefully and shoot a lot!
Note: I like to thank Ted for his input.
Please direct your questions and comment to
Fred the Re-Loader