Before committing to a military-to-sporter conversion project, it is crucial to understand the rifle to be converted. There is probably no better source on the various Mausers, and how they work, than The Mauser Bolt Actions – A Shop Manual, by Jerry Kuhnhaussen (published and distributed by Heritage Gun Books). That book is filled with crucial information for the person who undertakes the home conversion of a military Mauser.
Of equal importance, the home gunsmith must understand his own limitations. Otherwise, the converted rifle may wind up in the trash, rather than in the hunting fields or on the target range. As an example, I wanted my converted rifle to have a streamlined bolt handle, rather than its unsightly military version. But, from the onset of this project, I knew I simply did not have the know-how, the experience, or the equipment necessary for that part of the conversion. Therefore, I farmed out that task to Bob Riggs, a nearby gunsmith who has had a lot of experience in such matters. As per my request, Bob cut off the old bolt handle and replaced it with a new handle which I had purchased from Brownells, the gunsmith supply house in Montezuma, Iowa. It was mounted to the Mauser’s bolt at the same angle as used by Winchester on its Model 70 actions.
As to the rifle’s new chambering, I gave some thought to one of O’Connor’s favorites, the 7mm Mauser (7X57) but finally decided on the 7mm/08 Remington instead. Handloaded to their full potential, these rounds are nearly identical ballistically. However, factory loads for the 7mm/08 Remington are loaded to much higher pressures (and velocities) than 7mm Mauser factory loads because the 7mm Mauser is chambered in many older, weaker actions. Further, although I handload almost all of my ammunition, there is always the chance of being on a hunting trip and, in a pinch, for one reason or another, having to rely on factory ammo. Thus, the nod went to the Remington round, which I consider completely suitable for medium big-game and for heavier varmints as well.
Of course, I needed a new barrel, and for that I contacted Douglas Barrels, Inc., of Charleston, West Virginia. That company has been supplying fine quality barrels — at reasonable prices — since just after World War II. And, besides, that business was located just a couple of hours’ drive from my home in Kentucky. A simple phone call to Douglas Barrels assured me that they could supply what I wanted. First, however, they wanted to test the hardness of my Mauser’s action to make sure it was suitable for the conversion I had in mind. I took the action to them, and it passed the test.
Just a few days later I had a new Douglas XX, “air-gauged” premium barrel in hand. I had opted for a medium-weight sporter barrel 24 inches in length. The barrel was delivered in the white, threaded for the Mauser action, and was chambered for the 7mm/08. The rate of twist was one turn in nine inches.
Since I would be barreling the action myself, the folks at Douglas had deliberately cut the 7mm/08 chamber slightly deeper than necessary to allow for proper headspacing. Following the instructions accompanying the barrel, I managed to headspace the barrel and mount it to my action using my small Smithy lathe, depth gauges, headspace gauges, a barrel vise and wrench, and, most importantly, a lot of patience. It turned out just fine.
After the rebarreling process was completed, the metal surfaces of the barrel, action, floorplate and new bolt handle were hand-polished down to a 400-grit finish using emery cloth. Although there was some pitting on the action, it was quite shallow, so the polishing was not quite as tedious as I had feared. I also thinned, contoured and polished the trigger guard, which added remarkably to the rifle’s overall appearance.