Bolt Action Rifles. Wayne Zwoll

An M91 carbine version had a 17.63” barrel. The principal supplier of these rifles and carbines was Ludwig Loewe & Co., Berlin, who made 180,000 rifles and 30,000 carbines. DWM, of Germany, also made a quantity of the Argentine rifles. Peru, Columbia, Bolivia and Ecuador also adopted the M91 as their military arm.

      M91 Spanish Mauser

      In 1891 Spain became interested in these new smokeless powder rifles and, mostly for trial purposes, bought about 1800 of them in caliber 7.65mm. Known as the Spanish Model 91, it was essentially the same as the Turkish M90. Few were made and therefore the M91 Spanish rifle is very scarce today. Spain did adopt the carbine version, almost the same as the M91 Argentine carbine, and since more of these were made, the carbine is more common than the Spanish M91 rifle.

      M91 Argentine Mauser action.

      The Spanish M91 Mauser action differs from the Turkish M90 in that it has a small spring built into the right locking lug on the bolt to prevent double loading. The Belgian M89, Turkish M90 and Argentine M91 actions were made without this feature. It is possible, therefore, to double-load those rifles unless the bolt is fully closed and locked when chambering a cartridge.

      Normally, in these rifles, the cartridge is pushed into the chamber by the bolt, and not until the bolt is turned down and locked does the extractor slip over the cartridge rim. Therefore, if a cartridge is chambered, and the bolt is not fully closed, on withdrawing the bolt the cartridge will be left in the chamber. Then, on closing the bolt again it would pick up another cartridge, and its bullet would strike the cartridge already in the chamber. This is not only annoying, but could discharge the chambered cartridge should the pointed bullet strike the primer hard enough. The bolt head recess of the Spanish M91 is so undercut that, on pushing a cartridge from the magazine, the cartridge head slides directly into the bolt face recess, under the extractor hook. Held there under tension by a small spring in the right lug, if the bolt is not fully closed, the cartridge will be extracted and ejected when the bolt is drawn back.

      The Actions

      As already noted, except for minor differences, the M89 Belgian, M90 Turkish, M91 Argentine and M91 Spanish Mauser actions are essentially alike. I suspect, therefore, that practically all action parts are more or less interchangeable. At any rate, all of them were made for the 7.65mm Mauser cartridge. Since the M91 Argentine rifles and actions appear to be the most common, I have chosen this action to describe in detail. The description following applies to the other actions as well— except for the few differences already mentioned or to be noted later on.

      The one-piece receiver is a machined steel forging. The recoil lug, integral with the receiver, is located about 1.00” back from the front edge of the receiver. The front part of the receiver ring is round, The bottom of the receiver, from the recoil lug to the rear of the magazine, is flat. The magazine well opening is milled in the center of this flat area. The receiver ring is threaded inside to accept the barrel shank. The barrel has a short shoulder that butts against the front of the receiver when the barrel is tightened. The M89 Belgian rifles with the barrel jackets have about 9/32” of the front outside of the receiver threaded for the barrel jacket collar.

      M91 Mauser action with bolt open.

      The receiver is the same width from receiver ring to bridge, making the left side of the receiver ring, side wall and bridge a smooth, rounded surface. The front part (about ½”) of the bridge is the same diameter as the receiver ring. A rectangular notch, milled into this part, forms the charger guideways. The rest of the bridge is milled thinner to reduce weight. The receiver ends in a tang about 2.3” long.

      The one-piece machined bolt has dual-opposed locking lugs on its forward end. These engage matching recesses in the receiver ring and hold the bolt locked against the barrel when the action is closed. The right (or bottom) locking lug is solid, while the left (or top) locking lug is slotted to allow the ejector to pass.

      The bolt face is recessed to a depth of about .120”. Except for a shallow notch in the bottom of the bolt face, narrow extractor and ejector slots, the cartridge head is surrounded by a ring of steel when the bolt is closed.

      The extractor is a thin piece of spring steel about l.460” long with a small hook on its front end to engage the cartridge rim. It is fitted into a slot and dovetail mortise, cut lengthwise in the head of the bolt body. Held in place in its recess by the dovetail mortise, the extractor is prevented from moving forward by a lip under its forward end, engaging a cut in the bolt head. On closing the bolt with cartridge in the chamber the extractor snaps easily over the cartridge rim.

      15-2 M91 Mauser bolt face.

      There is a small stud (pin) pressed into a hole in the right receiver ring locking recess. When the bolt is fully closed, this stud coincides with the hook end of the extractor. Its purpose is to support the end of the extractor and prevent it from springing too far should powder gases escape in the extractor area. Thus, with the bolt closed and locked, the extractor hook becomes part of the supporting rim around the cartridge head.

      The bolt handle, an integral part of the bolt body, has a short square base, a slender round shank and a round ball grasping handle. On most of the rifles the bolt handle is straight, while on the carbines it is generally bent down. Primary extraction power is achieved on opening the bolt—the base of the bolt handle contacts and moves over an inclined surface on the left rear edge of the receiver bridge.

      The bolt body is drilled from the rear to accept the firing mechanism. The coil mainspring is compressed over the stem of the firing pin, between the shoulder on the firing pin and the forward, threaded shank of the bolt sleeve. The rear of the firing pin extends through the bolt sleeve and is held in place by the cocking piece, threaded to the firing pin. The unit is retained in position by the bolt sleeve, being threaded into the rear of the bolt body. A small rib on the firing pin and a matching groove in the bolt sleeve, through which the firing pin moves, prevents the firing pin from turning in the cocking piece. This rib is of such length that in assembling the firing pin parts, the cocking piece is turned on just far enough for correct firing pin tip protrusion when the cocking piece is threaded against the rib.

      There are two notches at the rear of the bolt into which the cam or sear of the cocking piece can fall. A deep notch coincides with the cam on the cocking piece when the bolt is fully closed and locked, allowing the firing pin to move forward under mainspring tension for proper firing pin protrusion and ignition. On raising the bolt handle, the inclined surface of this deep notch moves the cocking piece, firing pin, and firing pin tip back within the bolt face. When the bolt handle is fully raised the cam on the cocking piece falls in the shallow notch. In this second position, the firing pin tip is still within the bolt face and prevents easy turning of the bolt sleeve when the bolt is drawn back. The rifle cannot be fired unless the bolt is closed enough to allow the cocking piece to fall within the deep notch; in which case, the locking lugs are engaged in the receiver and lock the bolt closed.

      No provision is made to block the sear when the bolt is not fully locked. The action is cocked on the bolt’s final closing motion—the sear engages the cocking piece and holds it back when the bolt is closed. The firing pin can be lowered, without snapping the action, by holding the trigger back as the action is closed.

      The wing-type safety is fitted lengthwise into a hole at the top of the bolt sleeve. A small spring-loaded plunger in the safety wing engages a shallow groove in the bolt sleeve, holding the safety in place; shallow detents at either end of the groove provide the “off ” and “on” safety positions. Swung to the left, the safety is disengaged, allowing the action to be operated. When the action is closed and the firing pin cocked, swinging the safety to the vertical or to the far right position locks the bolt closed, so it cannot be opened, and holds the cocking piece from contact with the sear. The safety can also be swung to the right, when the firing pin is uncocked, to lock the bolt.