Building a Custom Mauser, Part Two

Last time, we separated our Mauser action from its old military barrel and finished polishing it to our satisfaction. If we are using Weaver-type scope mounts the rear receiver ring has been ground down and shaped to accept them. Let’s proceed to the next steps on my list. First, we’ll shape the bolt handle to accept a scope. The bolt handle on a Mauser goes straight up over the receiver when worked.

That’s not a problem since these rifles were made for open sights, however, this must be corrected for a scoped hunting rifle. There are several ways this can be accomplished. If you are going to use anew bolt handle cut the old one off using a cutter attached to an air compressor, if you have one. If you don’t a Dremel tool can serve, but it will take longer and burn up a few cutting wheels. The bolt and new handle are then held in a nifty little bolt-welding jig from Brownells to join them.

Use of heat shielding paste and a heat sink made specifically for this purpose is mandatory to make sure the original heat treatment of the bolt is not compromised. TIG (tungsten inert gas) welding is supposed to be a little cooler than other types and irritating pits in the weld can also be lessened according to the skill of the operator. Much has been made about matching the filler rod to the bolt, but I’ve found that any rod you would use for most modern steels will work perfectly.

TIG is one kind of welding best left to professionals and decisions about what to use should be theirs. After welding, the bolt is shaped and polished to fit under a scope. Another method of shaping the bolt is to leave the military one in- From top to bottom: Standard military, Numrich Arms, Forged, TIG Welded. tact and heat it with an oxyacetylene torch to bend it in place. Brownells also sells a fixture for this purpose as well as the needed heat sinks and heat shielding paste too.

The last approach I’ll discuss is replacing the issue bolt with anew bolt body from Numrich Arms that has the handle already shaped. When purchasing this unit I also ordered anew magazine box and bottom metal that has a push-button release latch to drop the floor plate. These worked well except for having to tweak the release latch so the floor plate wouldn’t drop open under recoil. Also, I had to mill out the rear action hole on the trigger guard just a smidgen to fit my particular action.

Sometimes it seems that no matter what part you buy for a gun that is supposed to be a "drop-in" fit you

.35 Whelen rounds are shown for comparison. still have to grind a little here or fi le a little there. I guess that’s why we are called gunsmiths and not parts assemblers. Lapping Bolt Lugs With the bolt handle taken care of, it’s time to lap the bolt lugs. This means that the inside of the lugs must mate perfectly with the lug recess in the receiver. Since we are probably working with an action that has mismatched numbers on the bolt, chances of being able to skip this step are slim.

Twenty-fi ve percent contact on each lug might have been considered good enough for whichever government’s work that originally built the rifle. Mark each lug surface with machinist’s dye and push the bolt into the action. While putting pressure on the bolt to the rear against the recess, work the handle up and down a few times and check your results. The places where the dye is rubbed off are making contact. Like I said, don’t expect to see 100 percent.

Even rifles with matching numbers will probably have no more than 25 percent on one side and maybe 50 percent on the other, if that. Many commercial bolt-action rifles I’ve checked have no better than this, so it would be foolish to expect better specs from rifles produced by the millions during the hurry-up of wartime. Once lug contact has been assessed we will improve it as needed. Coat the inside bolt lugs with abrasive grit and push them into the lug This takes the place of thumb pressure.

The astute reader will note that a Mauser 96 action is shown, however, the principle is the same. raceway so it stays on the bolt. Work the bolt while maintaining steady pressure on it. Brownells has a great spring-loaded tool that makes this job a lot easier than holding the bolt steady with your thumb. It can be ordered with threaded sleeves to accommodate different actions including Enfields, Springfi elds, Remington 700, and model 70s as well as small and large-ring Mausers.

This tool works by holding the bolt against the inside of the raceway while the bolt is rapidly moved up and down to mate the two surfaces. A short throw only is needed for this process. Mov-

All must be degreased and be in excellent working order. The military two-stage trigger should not be overlooked as an option for custom rifles. A little tweaking here and there can give an excellent trigger that some clients will appreciate. ing the bolt back and forth as far as it will go defeats the purpose by throwing off the grit. After about 50 throws add some more grit, then do 50 more. Check your progress by using machinist’s dye to coat the lugs and see how much is wiped off when the bolt is sent home.

We are looking for almost 100 percent contact. There is a third lug on the Model 98 bolt at the rear. This is a safety feature to stop the bolt from flying out in case of a catastrophic failure. Trying to lap this bolt in is a futile project in most cases because you would grind the front lugs to a nubbin before getting good contact with the rear. If you do find you are getting contact it is just icing on the cake. In any case it’s not necessary to worry about it.

I have seen 320 grit abrasive paste recommended by some to do this job. When you’re getting towards the end I suppose it will give a nice finish, but for the initial process I use valve-grinding compound commonly and cheaply found at any auto store. You’re hand is going to Minor fitting is required to install this safety. Minor fitting is required to use this safety. get tired after the hundreds of bolt throws it takes to do this job right and it doesn’t hurt to use a coarser grit to start.

Finish up with 320 if you want to. Also, if you don’t have any machinist’s dye just use a black felt-tip marking pen to check your progress. Works for me.

A mirror finish is not necessary for smooth bolt operation. 220 grit paper is all that’s needed. A mirror finish is not necessary for smooth bolt operation. Now we’ll drill and tap for scope mounts: A jig made specifically for this purpose is mandatory. No "eyeballing" here unless you want your scope to be cocked off-center. Forster makes the Cadillac of these tools and it can be used for open sight installation as well.

An inexpensive jig from B-Square is available from Brownells and works very well for installing the two-piece Weaver and one-piece Leupold and Redfield mounts that most of us use. After setup it’s a simple manner to drill the holes in the action that are needed. The jig comes with a drill guide that ensures proper positioning. A #31 drill bit is used for the 6×48 mount screws that are supplied with the Weaver bases.

I use a Tru Tapper, also from B-Square, to absolutely line up the tap with the holes utilizing the rigidity of the drill press or mill. This is best accomplished by leaving the action in the jig and vise, chucking the Tru- Tapper, and lining up on a milling table. A tap guide is also supplied. B-Square’s directions include holding the action by hand on a solid table while drilling. I guess you could do this if you had three hands, but I clamp the jig in a sturdy vise on a milling table and go from there.

Use the directions given and go slow. Don’t force your taps or they will break. This is not a total disaster as some would have you believe, provided you have a broken tap remover on hand, but it is best not to This is a small modification but one your customer will appreciate. break it in the first place. Back off as needed and let the chips out. I allowed my fifteen-year-old grandson to do this job with my supervision for his education, so don’t be intimidated.

Different drills and taps are needed for the 8×48 holes sometimes recommended for the big kickers, but for the .30-06 class of cartridges I have not had a bit of trouble using the smaller screws. I use carbide-tipped drills for these old actions. If the actions are hardened it is only on the surface and can usually be cut easily with the

carbide drill. If you have something stubborn a carbide end mill can be used to "break" the surface and allow the drill to proceed. Some have recommended annealing the spots for the holes to soften them, however, since we are not going to re-heat treat this action I don’t think it is a good idea. By using heat paste and sinks and not grinding or otherwise overheating this action I don’t believe it is necessary to re-heat treat it as long as we are careful. Others may have different opinions.

If you want to get your action heat treated go to it. Bolt Release Lever This is a very important part of our rifle since the ejector is also housed here. I am assuming the lever snaps back into place when pulled open and there is no problem with the fixed ejector. Function of this part is critical and must be 100 percent. No shortcuts here. If it doesn’t work properly, that is the province of another article.

The serrations on top can be worn and rounded and need a little file work with a small triangular file to sharpen them slightly for better purchase. There are several ways to mount this lever on the action. I have even seen it modifi ed to put the serrations on the bottom for cosmetic reasons. I personally like it on top, but each of you must do your own thing with your rifle. That’s what makes it yours and that is what this article is about.

I also like to take this little gem that sits prominently on the left side of the action for everyone to see and polish it with 320 grit before rebluing. Jewelling is another popular treatment for this part as well as on the bolt itself. Sometimes I think this may be a little fancy for the plain hunting rifles that I usually put together, but if you and your customer like it, fine. Triggers The trigger is one of the most important parts of any rifle.

For the gunsmith working the 98 Mauser there are a lot of options. Removing and installing anew trigger on this type of action is easy. Drive out one pin and you’re there. No sense in wasting time talking about it. Triggers for this application are generally of two types Those that come with an integral safety that only blocks trigger movement and those that use a separate safety that mimics the original, locking the firing pin from falling as well as allowing clearance for the scope. Timney makes both kinds.

I will go as far as to recommend their triggers since they are easily adjustable for pull weight, creep and overtravel, plus they are probably the least expensive of the lot. There are others, such as Rifle Basics, Jewell and Fajan on the market and all will work well. It’s up to you to pick, but, for the money, Timney will not let you down. When buying a trigger without a safety, such as the Timney Sportsman, I use a Buehler-style two-position wing safety that is easy to install and does a credible job.

A small notch must be cut into the cocking piece to fit this safety. It works similarly to the original but fits well under a scope while still allowing complete access in the field. Other safeties such as the popular three-position side safety of Model 70 fame are available but must be fitted with special tools and a milling machine. This is not really a big deal for most gunsmiths, but this series of articles lean toward hand tools that even hobby gunsmiths have in their shop.

Whatever kind of trigger and safety you choose, after adjustment, the procedure of rapping the rifleon its recoil pad to see if the trigger breaks with the safety on and off and then pulling once on the trigger and releasing the safety to make sure the rifle won’t fi re is mandatory. These triggers all have a recommended range of pull weights from the manufacturer and complete instructions on how they are to be adjusted. Trying to beat them with a lighter weight of pull is a fool’s game.

One option usually not mentioned is tuning the original trigger to suit. You probably won’t get a pull weight of less than fi ve pounds or so, but you could be surprised as to what a good marksman can do with a crisp trigger in that range, especially since these rifles will not be lightweights. I personally like a twostage military trigger and think anyone can get used to the take-up easily. It may be safer in the field than a two pound break-like-glass number.

How to tune the military trigger is the subject of another article and I recommend considering it as I use them on some of my personal rifles. It’s all up to the ‘smith. Last Items The two last items on my list for working the action before barreling are polishing the bolt races and opening up the channel at the tang end to allow for more positive and smoother bolt operation. A heavy, well-made tool for race polishing is available from Brownells.

Although it’s nice to have, one could just as easily make a polishing block. The idea is not to shine the races to a mirror finish but to just smooth any irregularities or bumps in the raceway, which is all that’s needed. I usually use 220grit abrasive paper to knock off any rough spots. Shaping a small "Y" where the bolt cocking piece comes into the tang area is also one of those "a little bit will do ya"-type of operations.

A channel as big as the mouth of the Mississippi where it fl ows into the Gulf is not necessary. All we want is a little extra clearance. Follow the original lines and use a cutting wheel on an end mill or Dremel tool to clean it up. This could help a great deal if a fast extra shot is needed and is a nice professional touch your customer will appreciate. Next time we will rebarrel our rifle and set it in anew stock. AG