standard M98 military action made for the 8mm Mauser cartridge has a magazine length opening of approximately 3.320” and, therefore, is best suited to cartridges loaded to a slightly shorter overall length. The bolt face recess and extractor are correct for any centerfire cartridge of 30-06 head size. Therefore, without modifying the magazine, bolt head or extractor, the standard M98 military action will handle such cartridges as these: 243, 244, 6mm Remington, 257 Roberts, 7mm Mauser, 284, 308, 8mm Mauser, 358 and wildcats based on these cases. The unaltered actions will usually handle shorter cartridges quite well, such as the 22-250, 225, 220 Swift and 250-3000. However, for perfect feeding it usually is necessary to install a filler block in the rear of the magazine and use a shorter follower for the shorter cartridges.
One of the author’s favorite varmint rifles—a compact medium-weight rifle based on a shortened Model 98 action. It is a single shot, chambered for the 219 Donaldson Wasp. The medium-heavy 21” chrome-moly steel barrel has a 1:14 twist and is very accurate. Sighting is done with a very fine Unertl 1¼”Varmint scope of 10x. Stock is of ultra-fancy southern Iowa stump walnut, with the grip and forend checkered in a fleur-de-lis pattern.
Lengthening the magazine is not too difficult. This makes the M98 action suitable for cartridges slightly longer than the 8mm Mauser. By thinning the rear and front magazine walls and altering the loading ramp, or by moving the front magazine wall forward and altering the loading ramp accordingly, it can handle most 30-06 or 270 length cartridges. Then, by opening up the bolt face recess and shortening the extractor hook, the action can handle such short belted-magnum cartridges as the 264 to 458. Opening up the magazine and altering the loading ramp enough for such longer magnum cartridges as the 300 H&H Magnum is not recommended since this greatly weakens the receiver where it supports the lower locking lug.
Remodeling the M98 military action is made easier by a number of accessories offered especially for it. There are trigger shoes available for the trigger, replacement safeties which will clear the lowest mounted scopes, quick-release floorplate devices, set-trigger mechanisms, fully adjustable single-stage trigger mechanisms with or without slide-type safeties. There are more scope mounts made for the M98 action than for any other. If this is not enough, you can buy a stiffer mainspring to speed up the lock time (as well as making the action harder to operate). Last, but not least, chambered and finish-turned barrels are available in a number of popular calibers from several firms. Most of the accessories are easily installed by following the manufacturers instructions, but unless you have the proper equipment for barrel fitting, I suggest you let a competent gunsmith do that job.
If a hunting scope is to be mounted low and over the bore—the only way it should be mounted—then the main alteration will be to the bolt handle so it will clear the eyepiece of the scope. The bolt handle can be forged to a low profile, or the original bolt handle cut off and it, or a new bolt handle, welded on in the low profile position. I prefer the latter, using an electric weld to attach the new handle. There are several gunsmithing books available which give detailed instructions on altering bolt handles, drilling and tapping the receiver for sights and scope mounts, installing barrels and altering the magazine, etc. If you want to do this work, and don’t know how, get these books and find out. They include The Modern Gunsmith by W.J. Howe, Modern Gunsmithing by Clyde Baker and Gunsmithing by Roy Dunlap.
M98 Barrel Thread
Model 98 rifles have been made over a long period of time, in a number of countries and by many different firms. It is, therefore, natural to assume that not all of them were made with exactly the same barrel thread. What they all have in common is a Whitworth-type thread with a metric pitch. This is a 55-degree V-thread, usually with rounded bottom and crest. The metric pitch is very close to twelve threads per inch. The drawing of the barrel shank specification indicates the thread diameter is 1.100”, the length of the shank .625”, with a pitch of twelve threads per inch. The American standard V-thread has a 60-degree angle and it has long been a customary practice of American gunsmiths to use the 60-degree thread in fitting new barrels to Mauser actions, a practice that’s perfectly acceptable. Barrelmakers producing threaded and chambered M98 replacement barrels must of necessity cut a minimum thread, so that the barrels will fit in practically every M98 action—this is also all right since a slightly loose thread fit is permissible. The important thing for the amateur to understand is that the barrel must be turned in and “set up” very tightly. The flat breech end of the barrel should contact the collar inside the receiver rather than having the shoulder of the barrel contact the front of the receiver. The custom gunsmith, in threading a barrel for the M98, will cut the threads on the barrel to fit the individual action, and can achieve as tight a fit as he wishes— even with a 60-degree thread cutter.
Besides a fairly snug thread fit, the ideal fit is also to have both the breech end and the barrel shoulder contact the receiver, but with the breech end contacting the collar much more firmly.
M98 Military Rifles
This book is chiefly concerned with the actions of various centerfire turnbolt rifles and what can be done with them rather than with the original rifles. There were so many different military rifles based on the M98 action that to describe them all is beyond the scope of this book. For information on these many rifles, refer to our bibliography. The most informative of these titles are Mauser Bolt Rifles by L. Olson, Mauser Rifles &Pistols by Smith and Small Arms of the World by Smith.
A number of firms in Germany turned out huge quantities of M98 military rifles and it is estimated that several million had been made by the end of WWI in 1918. They were made by several commercial arms firms including Mauser, Sauer, Haenel and DWM. DWM made a million alone. The German government arsenals in Danzig, Erfurt, Spandau and Amberg also made vast quantities.
Model 98a Mauser Carbine, one of several German military shoulder arms based on the Model 98 action. The M98a was used mostly during WWI.
Another of the author’s favorite sporting rifles, this one based on the VZ-24 Czech Mauser action. The stock, of classic design, is made from a fine-figured piece of American black walnut. It has a 24” sporter barrel and a Weaver K-10 scope. The action has a very fine Miller single-set trigger. This particular action and rifle has seen a lot of service. The action was made in 1939 and the military rifle from which it was taken had seen hard use since the bore was nearly worn out when it was obtained in 1945. The action was first fitted with a 220 Swift barrel. After firing about 1000 shots through this barrel it was replaced with one in the 220 Improved Swift caliber. After firing about 1500 times, it was replaced with another one in 225 Winchester caliber, and that one finally replaced by one in 243 caliber.
In the years following WWI there was only limited production of the M98, but in the mid-1930s, when Hitler began rattling his saber, production again went into high gear. This time many more firms got into the act, including some in German occupied countries. No one knows how many million M98s were made from this time until the defeat of Germany in 1945, but the quantity was immense.
The principal M98 arm of the pre-1918 period was the rifle with a 29.13” barrel. The main carbine version of that period was the M98a with a 23.62” barrel. The most common M98 developed after WWI, and the principal shoulder arm used during the WWII period, was the M98k with a 23.62” barrel. There were other variations, too numerous to mention, plus several variations of sniper’s rifles used during both wars. The M98k carbine was developed in the mid-1920s and it eventually became the most frequently produced German military shoulder arm.
Markings
As
