September 23, 2010
The civilian conversion of military firearms for sporting use goes back hundreds of years. I can imagine some unknown musketeer looking at the matchlock he brought home from a long-forgotten war and thinking, "I bet I could make this darn thing a lot lighter and easier to hunt with if I just trimmed the stock up a bit here and maybe cut the barrel back a couple of inches." That tradition of modifying surplus or outdated military arms is still with us. Each year thousands of hobbyists take inexpensive surplus military arms and convert them for hunting or recreational shooting.
Conversions have been especially popular in the U.S. due to the availability of inexpensive surplus arms and the opportunity and natural resources that allow us to use 'em. This traditional activity, followed by thousands of hobbyists, may have reached its peak in the 1950s and '60s. The issues of Shooting Times from that era often contained articles on the sporterization of military arms. As a part of our commemoration of the 50th anniversary of ST, I'm working up a series of reports on how to convert a well-used bolt-action military Mauser into a sporter.
In Parts 1 and 2 of this series, a Czechoslovakian military Mauser from Century International Arms was rebarreled using a Brownells Shilen prethreaded, short-chambered barrel in .35 Whelen. During this process, the bolt lugs were lapped, the chamber was extended to full length, the rifle was headspaced, and a sporter-type bolt handle was welded to the bolt. With those steps done, a major portion of the project was completed. The next step is installation of the sights.
While it's possible and definitely easier to forgo open sights and just set up the rifle for a scope, I don't like to do that. Years ago on an out-of-state hunt I had my scope fog up to the point of being useless. Fortunately, my rifle had iron sights, and they allowed me to continue the hunt and bring home some meat. I've never forgotten that experience and generally always want to have a "back up" sight system in place. You never know when you'll need it, but when you do, you really do!
Keep in mind that this rifle is chambered for .35 Whelen, and I'll use it primarily for whitetail deer here in Missouri. Ranges tend to be short, so iron sights make a lot of sense. If I ever get a chance to hunt elk or larger game out West, I can always install a scope as I will go ahead and drill and tap the action for a Leupold one-piece scope base.
Something a bit unusual is that I also plan on setting up this rifle for a receiver peep sight. While I can, and still do, use open sights on some rifles, I really prefer a peep sight. It's easier for me to use, especially since I've had to go to bifocals. Besides, it's a great opportunity to look at some of the issues relating to installing a peep sight.
Accurate calculation of the sight heights requires the use of precision measuring tools such as a digital caliper.
The Williams front sight ramp was placed about 1 inch to the rear of the barrel's muzzle. Sights such as a Williams Firesight fiber-optic front sight insert provide a custom touch.
Once you have the front of the barrel measured, divide the results by two; that's the distance from the center of the bore to the top of the barrel. Next, take the height of your sight ramp, which is measured from the point where it touches the barrel to the bottom of the dovetail for the sight insert, and add this figure to the thickness of the barrel above the axis of the bore. Finally, add in the height of the sight insert. This will be from the bottom of the dovetail on the insert to the top of the sight blade. The final figure is the total height of the sight above the axis of the bore.
You'll want to go through the same process with the rear sight. Always keep in mind that you want to have both front and rear sights of the same height above the center of the bore. Some suppliers of sights, such as Brownells, will give you the critical height dimensions of the various sight components in their catalog descriptions. This information makes sight height calculations quite easy. In fact, Brownells provides a wonderful illustrated explanation in its catalog and a great instructional video on the website (Brownells.com). Between the two, you can't go wrong.
Ideally, a precision tool like the Forster Universal Sight Mounting Fixture is used to locate and guide the drill for the mounting holes. You will likely need to find a gunsmith to help you with this.
Two additional points you'll want to keep in mind: First, make sure your iron sights are high enough so they're not blocked by the receiver or your scope base. Also, when setting up the front sight, use the highest ramp you can along with one of the lower front sight inserts to obtain the correct sight height combination. A tall ramp with a short sight insert is much stronger and less likely to be damaged than a tall sight insert and a short ramp.
Install The Peep
After installing the iron sights, I then installed the Lyman receiver sight. It's actually easy to position this receiver sight. All you need to do is place a small machinist square with one leg on the bottom of the receiver and the other on the side of the sight that is placed on the right side of the receiver. When you do this, the Lyman Mauser sight will be correctly positioned. It doesn't get much simpler!
While it's possible to drill and tap a barrel or receiver without special tooling, I wouldn't recommend it. Ideally, you would want to use something like the Forster Products Universal Sight Mounting Fixture. This fixture ensures your drilled holes are perfectly centered on the barrel or receiver. Since most folks don't have one of these fixtures, you might want to take your sights and gun to a gunsmith to have the necessary holes drilled. You'll still have lots of work you can do to make this rifle your special and unique project.
When we get together again, I'll install a side-swing safety and an adjustable
trigger, and I'll do something a bit unusual with the military trigger guard. Until then, good luck and good gunsmithing!
Another custom feature on the author's Mauser is the use of a Lyman 57 SME adjustable receiver sight. A simple machinist square was used to position the sight at 90 degrees to the bottom of the receiver.