same power class as the 30-40 Krag and 300 Savage. It should not be confused with the smaller 303 Savage cartridge, nor is the 303 British interchangeable with any other cartridge, although its case is nearly the same as the 30-40.
The 303 British cartridge is reloadable. It uses standard 303 (.311”-.312” diameter) bullets. Lee-Enfield barrels have a left-hand rifling twist of one turn in 10 inches; bore (land) diameter is .303”, groove diameter about .314”. Most barrels have 5 grooves, although some late-manufactured No. 4 rifles may have 2-groove barrels. The No. 4 rifles made by Savage usually have 6-groove barrels.
* These first official Lee-design rifles had barrels cut with Metford’s segmental, shallow-land rifling. The Cordite powder then used was highly corrosive, soon ruining the Metford barrels. Enfield rifling—essentially similar to today’s standard rifling, and a Metford design too, in fact— offered much deeper, and somewhat wider, lands to the hot powder gases. Barrel life was considerably extended.
Mauser Miscellany FdH
The Model 98 Mauser 22 rimfire conversion unit installed in a WWI M98a carbine.
Erma 22 Rimfire
Conversion Unit
LUGER FANS HAVE long been familiar with the Erma 22 rimfire conversion unit made for that pistol. Not so well known, however, is the 22 Long Rifle conversion unit this firm (Erma Werke in Germany) made for the M98 rifle. I believe this unit was made in the 1920s and ’30s, but I don’t think it has been made since before WWII. The conversion unit illustrated here is unmarked (except for serial numbers and proof marks), but I believe, and several other Mauser fans agree with me, that this is the Erma unit.
This, or a similar conversion unit, was also used by the military in Geramny for training purposes. It was called the “Model 24 Insert Barrel.” It was most likely first made as a single shot, then as a repeater later on. These were probably by Erma.
This conversion unit has the basic mechanical components of a rifle—a complete action and barrel assembly but minus sights, trigger and stock. The action is a turnbolt, the cartridges fed into it from a detachable box magazine. Only the bolt and floorplate/follower assemblies must be removed from the M98 rifle for the unit to be installed. It was made primarily to be used in any 8mm M98 military rifle or carbine having a barrel at least 24” long, but it can also be used in 8mm Mauser sporting rifles with similar length barrels.
The receiver of this unit fits in the receiver of the M98 in place of the regular bolt. The main length of the barrel is only slightly smaller than the land diameter of the 8mm barrel, so it fits snugly in the bore. The breech end of the barrel is the size and shape of the chamber. On the breech end there is a collar and, between this collar and the receiver, there is a two-piece threaded adjustable sleeve arrangement. One part of this sleeve has two lugs which can be rotated to engage in the locking lug recess in the M98 receiver. When the unit is inserted into the M98, the outer sleeve with its lugs is turned clockwise to engage the lugs in the receiver, then the inner sleeve is turned clockwise to secure the unit in the rifle. Holes are provided in both outer and inner sleeves so that they can be turned with a tool, such as a nail with its point filed off.
The front part of the unit’s receiver has two openings; one at the bottom for the magazine, one on the top right for the ejection port. The rear part of the receiver, larger than the main part, is made to fit in the larger opening in the M98 receiver and over the top of the tang. This prevents the entire unit from turning in the receiver. The barrel is attached to the receiver with two cross pins.
The bolt has three main parts; the two-diameter bolt body, which contains the long extractor and separate firing pin; the bolt handle sleeve, which threads into the rear end of the bolt body, and the firing mechanism composed of striker, mainspring, cocking piece, safety and striker nut. A slot is milled in the thick rear part of the receiver for the bolt handle, and a notch cut in this slot for the base of the bolt handle to lock the bolt in the receiver when the bolt is closed. The bolt stop is merely a shoulder in the rear zig-zag slot for the bolt handle.
The cocking piece has a projection which extends through a narrow slot in the bottom of the receiver and into the cocking cam raceway in the M98 receiver to engage the sear. The striker is cocked entirely on the closing motion of the bolt. When the action is cocked, the wing safety can be rotated down to engage over the end of the receiver.
The detachable five-shot box magazine is well made. The milled follower is guided inside the magazine by its rounded front end moving in a cylindrical guideway built into the front of the magazine. The coil magazine spring is positioned in this cylinder. The magazine is precisely and securely held in position through a hole in the floorplate, inside of which is attached a sheet metal guide housing. A notched flat spring attached to the right side of the magazine holds the magazine up when the notch engages over the edge of the floorplate. The bottom of the magazine and its release spring project below the magazine floorplate so that it can be easily grasped and removed.
The unit illustrated here is very well made, fitted and finished, and all the major parts are numbered.
To install the unit in an M98 rifle, remove the bolt assembly, floorplate, follower and follower spring. Turn the locking sleeve on the Erma unit so the hole in the rear part of this sleeve is up, then insert the unit into the receiver and barrel as far as it will go. Pull the trigger or open the bolt of the unit so it will stay forward. Now rotate the locking sleeve ¼-turn clockwise until the locking sleeve can be turned. When the locking sleeve is engaged, turn the adjustment sleeve clockwise until tight. Install the floorplate, slip in the magazine and the rifle is ready to fire.
I fired the conversion unit shown here at an indoor 50-foot range, using standard velocity 22 Long Rifle ammunition. Taking a fine bead over the crude military sights on the M98a carbine in which this unit was fitted, and with the rear sight elevated to the 600 meter setting, the shots zeroed perfectly in the target. Considering the crude sights, accuracy was quite good, suitable for plinking and small game at close range. The unit functioned perfectly and there were no feeding, ignition or extraction problems.
Close-up of the conversion unit, shown with bolt open.
The complete 22 conversion unit for the M98 rifle in 8mm (8x57 or 7.9x57) caliber. Unit is shown with bolt open. The Erma units were usually supplied in a partitioned wood box with an extra magazine and instruction sheet.
These Erma conversion units are seldom seen today, but they’re an interesting extra for any Mauser rifle collection.
Mauser M98 Breech Cover
One of the rarest accessories ever made for the M98 military rifle was a breech cover. During the early part WWI, the Germans discovered that their M98 was not as foolproof as it could have been. The main fault showed up when the rifle was used in all sorts of battle and weather conditions— in mud-filled trenches, on dusty, sand-swept battle grounds, or in freezing rain. Then it could become inoperative, or its operation affected, by the entry of foreign material into the action.
Among the several openings in the M98 where foreign material could easily enter, the largest is the thumb notch in the receiver wall, which exposes the left locking lug raceway. This opening is large enough, front and rear, to allow foreign matter to enter the locking lug recess in the front of the receiver and
