Читать книгу Bolt Action Rifles - Wayne Zwoll - Страница 16

German Model 88 Commission Rifle FdH

(Pictured above) M88 (KAR.88) German Commission carbine.

THE GERMAN MODEL 88 rifle, adopted in 1888 and correctly known as the German Commission Model 88, was the official German military rifle until succeeded by the famous Model 98 Mauser in 1898. The M71 Mauser single shot and the M71/84 Mauser repeater, both in 11mm caliber, preceded the M88 as the official German military shoulder arms.

The 88 rifle was developed by a group of men, headquartering in Spandau, Germany, who formed the German Military Rifle Testing Commission, thus its unusual name. Although it has some features taken from earlier and Mannlicher rifles, it is neither a “Mauser” nor a “Mannlicher.” A well-planned and thought out rifle, the main features of the receiver and bolt were used long afterward on the Mannlicher-Schoenauer sporting rifles.

Developed with the M88 rifle was Germany’s first small-caliber smokeless military cartridge. It was a bottle-necked, rimless cartridge of 8mm caliber, and the forerunner of the world famous 8x57 Mauser cartridge.

Vast quantities of M88 Commission rifles and carbines were made in various German government arsenals. These rifles were usually marked “GEW.88” stamped on the left side of the receiver. “GEW” is an abbreviation of the German word Gewehr, meaning rifle. The rifles had a 29.1” barrel, the carbines with a 17.62” barrel; the receivers were usually marked “KAR.88.” “KAR.” is an abbreviation for Karabiner, meaning carbine. Both the rifle and carbine were made with a barrel jacket, a thin-walled steel tube covering the entire length of the barrel. The jacket is large enough to leave an air space between the jacket and barrel. The carbine has a turned-down spoon-shaped bolt handle, while the rifle has a straight bolt handle with a round grasping ball. A great many of these arms were also made in plants in Austria, including the great Steyr works.

As these rifles became obsolete, many of them turned up in the United States. During the 1920s and ’30s, the M88 Carbine was especially common, many of them used “as issued” for hunting big game.

Action Construction

The receiver is milled from a one-piece steel forging. The receiver ring is round except for a very small projection underneath which forms the recoil lug. The small recoil lug required that a square-stemmed cross-bolt be used in the stock—the recoil lug engaging a groove milled into the cross-bolt. A longer projection at the bottom rear of the receiver ring forms the cartridge guide. The front of the receiver is threaded on the outside for the barrel jacket collar and on the inside for the barrel shank. The breech end of the barrel abuts against two semi-circular shoulders milled inside the receiver ring; these shoulders partially ring the bolt head. To the rear of these shoulders, the inside of the receiver is milled out to receive the locking lugs of the bolt.

The rear part of the receiver, commonly called the bridge, is slotted on top so that the bolt handle can pass through it when opening and closing the action. A simple bolt stop is positioned on the left side of the receiver bridge and hinged there by a pin through a stud on the receiver. Tension is provided to the bolt stop by a small coil spring.

The bolt assembly is comprised of the bolt body with its integral handle, bolt head assembly and firing mechanism. The bolt body is a cylindrical, hollow tube drilled from front to rear. The opposed dual locking lugs are on the extreme forward end of the bolt body and engage matching recesses in the receiver when the bolt is closed.

The left (or top) locking lug has a narrow slot cut through it. This allows the bolt to pass over a finger on the end of the bolt stop—this finger activates the ejector when the bolt is opened. The right (or bottom) locking lug is solid with its top front corner beveled to match a similar bevel machined on the top shoulder inside the receiver ring. This provides the initial extraction camming power on opening the bolt.

The separate bolt head is made to fit closely on and inside the front end of the belt body. A small lug on the stem of the bolt head fits in a matching circular recess cut inside the bolt body to hold the two parts together, except when the bolt head is rotated to a certain position. The small spring extractor is mortised into a groove in the right side of the bolt head. The extractor easily snaps over the cartridge rim when the bolt is closed on a cartridge singly loaded into the chamber, or on a cartridge that is chambered from the magazine ahead of the extractor. A lug on the left of the belt bead matches the left locking lug on the bolt and contains the very small ejector. On some bolt heads, the ejector is held in place by a small screw, while on others friction alone holds it in place when the bolt head is disassembled from the bolt body. The end of the ejector protrudes through a hole in the face of the bolt head recess. The face of the bolt head is recessed for the cartridge head. On some bolt heads, the rim of the recess covers about 75 percent of the circumference of the cartridge head. On others, the rim is not cut away at all— except for the extractor cut. The bolt head does not rotate with the bolt. It is prevented from doing so by the flattened end of the firing pin fitted into its slotted stem.

The rear end of the bolt has a hole that is smaller than the main hole through the bolt body. The mainspring is compressed between the shoulder formed by the smaller hole and the shoulder on the front of the firing pin.

German M88 (GEW.88) Commission rifle.

Close-up of the M88 German Commission carbine action.

The threaded rear end of the firing pin extends through the center of the cocking piece and is retained there by the firing pin nut. A flat spot on the rear of the unthreaded part of the firing pin matches a flat surface inside the cocking piece and prevents the firing pin from turning. A notch in the front of the firing pin nut engages the rear end of the safety when it is turned tight—to prevent the nut from coming loose. The rear, flared part of the firing pin nut has a narrow flange extending into the cocking cam raceway of the receiver and a wide flange, the size of the locking lug raceway, extending to the left. Their purpose is to deflect powder gases away from the shooter’s face—in the event of a ruptured primer or case head.

The rear end of the bolt body has a deep cam notch to engage the cam on the front of the cocking piece. When the bolt handle is lifted, the cocking piece is cammed back about .370”.the remaining cocking motion is done on closing the bolt. Essentially, the M88 is a “cock-on-opening” action, since the greatest amount of cocking is done when the bolt is opened. This action can be uncocked without snapping by closing the bolt while holding the trigger back. This should only be done on an empty chamber.

The wing safety fits into a hole bored longitudinally in the top part of the cocking piece. It is held in place by the firing pin nut. A small coil spring around the safety stems holds the safety back against the firing pin nut to prevent the nut from turning, yet allows the safety to be pushed forward so the nut can be unscrewed. It also provides tension to the safety so it will remain in the position to which it is rotated.

Rotating the safety to the “up” or “right” position, its forward end engages a notch cut into the rear of the bolt body, camming the cocking piece back slightly so it is free of the main sear and, at the same time, locking the bolt so it cannot be opened. Since the safety, safety spring, cocking piece, firing pin nut and firing pin are assembled as a unit, they all move as a unit when the action is cocked and fired.

The trigger assembly is a simple one, composed of a trigger, sear housing, sear trigger spring, trigger pin, sear pin and sear housing pin. The sear housing pin holds the assembly to the receiver. The trigger is the double-stage type. The first part of the trigger pull, quite long and light, nearly disengages the sear from the cocking piece. A shorter, but heavier, final pull disengages the sear from the cocking piece.

The trigger guard/magazine is machined and formed as a single unit. A long screw, through a hole in the rear of the trigger guard, threads into the tang of the receiver. A shorter screw, through a hole in the front of the guard, threads into a round stud, silver soldered to the barrel jacket. Both hold the action and barrel in the stock.

The trigger guard bow opening is long— the bow itself is very thick and wide. The magazine box, more or less a walled shell, extends below the stock line, forward of the guard bow, housing the various magazine parts which hold and guide the cartridge clip. It is essential that a clip be used in this action, since it is the clip that holds the cartridges in position in the magazine. I will go into more detail later.

A catch, which pivots on a screw and is given tension by a small coil spring, is positioned in the rear of the magazine. This catch has a hook on its upper end to engage and hold the loaded clip down. A button on the lower end of the catch protrudes inside the guard bow and can be depressed to release the loaded clip. The follower arm, positioned in the front of the magazine on a screw, is given tension by a heavy coil spring and plunger, located in a hole in the heavy front part of the magazine. The rear underside of the magazine is open to allow the empty clip to fall out. The remainder of the magazine opening is closed by a flat piece of steel, held in place by a screw.

The clip is a U-shaped piece of spring steel which holds five cartridges. The top and bottom of the clip are identical. The edges of the side are curved inward to hold the cartridges and to form guide or retainer lips when the loaded clip is in the action. Ridges inside the rear of the clip match the extractor groove in the cartridge head. When loading the cartridges into the clip they must be inserted with their heads engaged behind these ridges. The ridges thus hold the cartridges securely in the clip, and the rifle’s recoil cannot dislodge the cartridges forward from the clip. This clip form is of some advantage when soft point ammunition is used, as it will keep the bullet point from being battered—by striking the front of the magazine from recoil.

Two types of bolt heads used in M88 Commission rifles. Top: Bolt head with the wide extractor hook and undercut recess rim. When feeding from the magazine into the chamber, the cartridge head moves upward with the extractor hook engaging the cartridge. If the bolt is closed but not rotated and locked, the cartridge will be extracted and ejected on opening the bolt. Bottom: This is, perhaps, the earlier type of bolt head with the narrow extractor and a full-recess rim. The cartridge is pushed into the chamber ahead of the extractor, but the extractor hook cannot engage the cartridge head unless the bolt is fully closed and locked. With this bolt head, it is possible to “double load” the rifle. Unless the bolt is rotated and locked, the cartridge will not be extracted.

The loaded clip is inserted into the top of the opened action and pushed down against the tension of the follower arm until engaged by the clip catch. Since the top and bottom of the clip are identical, it isn’t possible to insert the clip incorrectly. As each cartridge is fed out of the clip, the follower arm raises the remaining cartridges in the clip—the clip remaining stationary. A fully or partially loaded clip can be released from the top of the opened action by depressing the clip catch. When all the cartridges have been fed from the clip, it will drop from the magazine of its own weight.

Military M88s are usually serial numbered. The full number is stamped on the receiver, barrel, barrel jacket and bolt. Other parts of the action may also be stamped with the same number or with part of that number. If all the numbers match, this indicates that all the parts are original. The date (year) of the rifle’s manufacture is usually stamped on the receiver ring. Commercial sporting rifles based on this action usually follow the serial numbering practice used on military arms, though they are not always stamped with the date of manufacture. Military rifles seldom have the caliber designation stamped on them. On sporting rifles, the caliber is usually stamped on the barrel, but it may be underneath the barrel, requiring the removal of the stock to see it.

Strong and Weak Points

The German M88 actions are well made, all the parts are of steel, machined and finished to close tolerances and properly heat-treated. The outside of the bolt body, the inside of the receiver and all the contracting surfaces of the firing mechanism within the bolt and receiver carry a very fine finish, resulting in exceptionally smooth and easy opening and closing of the bolt. Despite the slotted receiver bridge, there is little sloppiness of the bolt in the receiver, even when the bolt is open. Feeding of the cartridges from the magazine is smooth and reliable, and there is ample extraction camming power. The bolt stop is quite rugged; the safety positive. Although the bolt head is a separate part of the bolt, and the front end of the bolt is hollowed out to accept it, there seems to be ample metal at the front to adequately support the dual locking lugs.

This action, however, has more weak and undesirable features than strong ones. The weakest part is the very small extractor. Not only is it weak and delicate, but it can be lost easily when the bolt is taken apart. The ejector is small and delicate also.

The separate bolt head can be readily disassembled and can be easily lost—another undesirable feature. The bolt can be assembled in the action minus the bolt head, and it is possible to fire a cartridge in the rifle with the bolt head missing with unpredictable consequences.

The worst feature is the need for a special clip to hold the cartridges in the magazine. When the M88 rifle was used as a military weapon, with the ammunition supplied in clips, these clips were then expendable. However, when these rifles were used as sporting arms, the sporting ammunition was not furnished in clips, and their easy loss became a problem. A small device known as a “clip-saver” was developed to prevent the clips from dropping from the magazine. It was a small, sliding spring cover slipped over the rounded edges of the bottom of the magazine. Covering the hole in the magazine held the empty clip in the magazine. Commercial sporting rifles made on this action often had a hinged magazine hole cover serving the same purpose.

Another undesirable feature is the mass of metal attached to the striker, resulting in rather slow lock time. This mass includes the heavy striker, massive cocking piece, striker nut, safety, and safety spring.

No provision is made to allow powder gases to escape harmlessly from the action in the event of a pierced primer or ruptured case head. There are no gas escape vents in the bolt or receiver ring.

Minor design faults include the forward position of the bolt handle, inconveniently placed for rapid bolt operation. The split bridge design prevents installing a conventional receiver sight and also places some limitations on the choice of scope mounts which can be used. The magazine box extending below the stock line is also a nuisance in carrying the rifle. Although not an action fault, the barrel jacket is not a desirable feature.

Takedown and Assembly

Open the bolt and, while depressing the bolt stop, withdraw the bolt from the receiver. Disassemble the bolt as follows: Press the safety forward and unscrew the striker nut. Remove the cocking piece from the firing pin. Holding the bolt in the left hand, firmly grasp the bolt head with the fingers of the right hand and turn the bolt head ½-turn clockwise. Bolt head, firing pin and mainspring can now be pulled out of the bolt. The extractor is removed from the bolt head by raising the hooked end and sliding it forward. The ejector can be removed by pushing it back with a drift punch. Reassemble the bolt parts in reverse order, as follows: Lay the bolt on a table with the lugs to the right and the bolt handle toward you. Place the bolt head on the firing pin with the ejector lug aligned with the flat spot on the rear of the firing pin. Slip the mainspring over the firing pin. Now, grasp the bolt with the left hand and, with the bolt handle pointing toward you, insert mainspring, firing pin and bolt head into the front of the bolt. With the ejector lug pointing away from you, or opposite the bolt handle, push the bolt head into the bolt as far as it will go; then turn the bolt head ¼-turn counterclockwise so the ejector lug is aligned with the left locking lug. Place the cocking piece over the rear end of the firing pin, with the safety lug in line with the bolt handle. Insert the safety and spring into place with the safety wing to the left and, while depressing the safety, turn on the striker nut until the rear end of the firing pin is flush with the end of the nut.

Top view of the M88 German Commission action.

Remove the barrel, action and magazine assembly from the stock by removing the front and rear guard screws from the bottom of the magazine/guard. Remove the bolt stop by driving out the bolt stop pin from the bottom. Remove the trigger assembly by driving out the trigger sear pin. Depress the follower arm and insert a wire or brad into the hole exposed at the end of the follower plunger. Then remove the follower screw to remove the follower. Remove the magazine plate screw and slide out the magazine plate. Remove the clip catch screw and remove the catch and spring. Pull out the wire or brad from the follower plunger to move the plunger and spring. Reassemble in reverse order. Do not unscrew the barrel jacket or barrel from the receiver unless you have the proper tools available.

Remodeling

As soon as the M88 rifle had been adopted, German and other European gunmakers began making sporting rifles on this action. The practice continued long after the M88 was dropped in favor of the far better M98 Mauser.

At first, these sporting rifles were generally chambered for the 8mm cartridge originally designed for this action. This round was originally known as the 7.9mm, and later on as the 7.9x57mm or 8x57mm Mauser. Its commercial designation was 8x57J, the “J” meaning Infanterie.^* This cartridge was loaded with a bullet of .318” diameter to match the normal bore (.311”) and groove (.320”) diameters of the military barrel. Therefore, the correct ammunition to use in the military M88 rifles and carbines is the 8x57J. The sporting rifles were also chambered for the 6.5x57mm, 7x57mm, 8x56mm, 9x57mm and other cartridges, all of them originally factory loaded to breech pressures of less than 45,000 psi. That was considered maximum safe working pressure for this action.

The clip of the M88 will accept and handle any rimless cartridge having the standard 30-06 head size and those that are no more than about 3.250” long. Cartridges feed in a straight line into the chamber, and even those as short as the 35 Remington will function very nicely. In past years, I have seen several M88 carbines rebarreled to 35 Remington, and their owners liked them very much for hunting deer. I have also seen some rebarreled with an M98 Mauser 8mm barrel so that commercially loaded U.S. 8mm Mauser hunting ammunition could be safely used. U.S.-loaded 8mm Mauser cartridges show a breech pressure of less than 40,000 psi and, therefore, are quite safe for these old actions if the new barrel fitted has a groove diameter matching the .323” diameter bullet used in these cartridges. In fitting the M98 barrel to this action, it is necessary to turn and thread a new shank.

M88 German Commission action, opened.

German Model 88 Commission Rifle

General Specifications

Type . . . . . . .Turnbolt repeater.

Receiver . . .One-piece machine steel forging. Slotted bridge.

Bolt . . . . . . .Two-piece with dual-opposed locking lugs on forward part of body. Separate, non-rotating bolt head.

Ignition . . . .One-piece firing pin, coil mainspring, cocking piece and firing pin nut. Cocks on opening bolt.

Magazine . . .Single column, non-detachable box magazine. Five-shot capacity. Special clip needed.

Trigger . . . . .Non-adjustable, double-stage military type.

Safety . . . . .Rotary wing-type safety built into bolt sleeve. 180° swing from left to right, locking striker and bolt when in the “up” or right-side positions.

Extractor . . .Machined, one-piece spring type built into bolt head.

Bolt-stop . . .Separate, hinged to the rear left of receiver. Stops bolt travel by contacting left locking lug.

Ejector . . . . .Plunger type, built into the bolt head, activated by an integral finger on the bolt stop.

When the German gunmakers used the M88 action for a sporting rifle, they seldom used the barrel jacket. The front guard screw was threaded into a nut inletted into the barrel channel in the forend. When using the military action without the barrel jacket, the collar on the jacket can be used to cover the threads on the front of the receiver. For looks only, the new barrel should have a shoulder like any sporting rifle barrel, as shown in the drawing of the barrel shank specifications. German gunsmiths installed some double-set trigger mechanisms in these actions, and I see no great problem involved in installing those made for the M98 Mauser in the M88 action.

The German gunmakers also used the basic M88 action, but minus the magazine, for making up many fine, lightweight shot target/hunting rifles. I once owned and used a rifle of this type chambered for the 5.6x52R (22 Savage Hi-Power) cartridge. The receivers of these rifles have a solid bottom, and the action is almost always fitted with a fine double-set trigger. The barrels are usually partially octagonal, fully octagonal or ribbed, and fitted with sporting sights. When the 219 Zipper cartridge was introduced in 1937, I made up a single shot varmint rifle on the military M88 action. I left off all the magazine parts, filled the magazine well opening in the receiver with an aluminum block and used a Krag trigger guard. The bolt face was easily opened to accept the rimmed 219 case. It was one of my first successful varmint rifles, and it dropped many a crow in the Iowa farm country where I lived.