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
