Bolt Action Rifles. Wayne Zwoll
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The firing pin and mainspring are inserted through the front of the bolt, the mainspring being compressed over the firing pin stem between a shoulder on the front of the firing pin and a shoulder in the rear of the bolt body. The heavy cocking piece fits over the rear end of the firing pin, held there by the firing pin nut, which is secured to the firing pin with an interrupted lug arrangement. Flat surfaces on the rear of the firing pin, engaging a matching hole in the cocking piece, and the flattened front end of the firing pin, engaging a matched slot in the bolt head, prevent these parts from turning on the firing pin.
A cam projection on the cocking piece, matching a notch in the rear of the bolt body, cocks the firing mechanism when the bolt handle is lifted. This cocking action is easy because of the smoothness of the contacting metal surfaces. Since the firing pin nut, cocking piece, safety and safety spring are part of the firing mechanism, and are attached to the firing pin, lock time is a bit sluggish, but ignition is positive because of the weight of these parts.
The wing safety is positioned in a hole in the upper part of the cocking piece and into an extension of the cocking piece which extends forward into the slot in the receiver bridge. It is tensioned by a short coil spring which fits over the stem of the safety. This keeps it pushed back against the firing pin nut, which holds the safety in place, and which in turn prevents the firing pin nut from being turned unless the safety is pushed forward. When the action is cocked, swinging the safety up and to the right locks both bolt and cocking piece. This is accomplished by the end of the safety stem engaging in a notch in the end of the bolt. With the action uncocked (striker forward), the safety can be depressed and swung over to the right to lock the bolt, but this is to allow the bolt to be disassembled easily, rather than to lock the bolt in the action.
Main parts of the military M-S action, showing complete bolt assembly at top, receiver in the center, and detachable rotary magazine assembly at bottom.
One very small gas escape hole in the bolt is the only outlet should gas enter the firing pin hole. This hole, just forward of the mainspring shoulder on the firing pin, is exposed in the front of the receiver opening when the bolt is closed and locked.
The trigger assembly consists of trigger, trigger pin, sear, sear pin, sear lever, sear lever pin and sear lever spring, mounted under the receiver on the sear lever pin. The trigger has the usual two humps that provide the standard double-stage military pull.
The trigger guard bow, large and heavy, is held in place in the stock, along with the rear part of the receiver, by a tongue-and-groove arrangement with the receiver at the front, and by the rear receiver screw, which passes through the rear of the guard and stock, and threads into the receiver tang. The front of the receiver is held in the stock by a screw that runs through an escutcheon in the bottom of the stock.
Top view of the Greek military Mannlicher-Schoenauer action.
Issue military M-S trigger (right) can be modified and improved, as shown at left, by installing an adjustment screw on its upper end, plus bending and straightening the lower end.
The Schoenauer Magazine System
The most interesting feature of the Mannlicher-Schoenauer action is the box magazine, whose spring-tensioned rotary spool feeds cartridges into the path of the bolt.
The heart of the magazine is the spool, held in upright standards over a box-like trough, much like an old-fashioned chicken feeder. The spool has 5 shallow grooves that conform to the diameter and shape of the 6.5 M-S cartridges. The cartridges are not separated except for the first and last, which are divided by a wing that is actually the follower. A coil spring inside the spool provides the rotary power to feed the cartridges into the action. Bearings at the spring ends provide the means to anchor the spool to the standards and to keep the spool wound.
The floorplate is attached to the bottom of the box via a stud and spring clip, allowing the plate to rotate. The fore and aft magazine projecting walls under the receiver are milled out to accept the magazine box. Their inner ends are grooved for the ends of the floorplate so the magazine is locked in place when the floorplate is lengthwise with the action. A spring clip in the bottom of the magazine box, engaging a recess in the floorplate, locks the floorplate in its lengthwise position and, when depressed, allows it to be rotated.
The magazine well opening, in the left side of the receiver, slants slightly in that direction so that as the cartridges are fed into and out of the magazine, they are guided around the spool and magazine box. Circular cartridge guideways about ¼” wide, built into the front and rear of the magazine opening in the receiver, and in the magazine box, hold the cartridges in a circle against the spool, allowing the cartridges to move around without much friction.
To allow insertion of cartridges into the magazine and to prevent them from coming out again, a cartridge-stop was fitted into a milled cut in the underside of the right receiver wall. It is held in place, and pivots on, a screw through the front of the receiver wall. It is tensioned by a small coil spring. The rear part of the cartridge-stop projects through a hole near the rear of the right side of the magazine well opening, and a checkered projection protrudes through another opening in the top of the wall.
On loading a cartridge into the magazine and pressing it down with the thumb, the cartridge-stop is depressed as the cartridge moves over it; when thumb pressure is removed, the cartridge, forced up by the tension of the magazine spool, is halted by the bolt-stop so that only part of the cartridge projects in the path of the bolt. The magazine can be fully loaded by inserting one cartridge at a time, or loaded by stripping cartridges from a charger clip. The loaded magazine can be quickly emptied by merely pressing down on the checkered projection on the bolt-stop.
The Schoenauer magazine system is reliable in every way. It holds five cartridges in a space only slightly larger than needed for a staggered-column magazine. Feeding is positive and smooth, and there is only one path for the cartridges to take as they are fed into the chamber. The spool prevents cartridges from moving forward as the rifle recoils. This prevents bullet point mutilation. Finally, the magazine box and spool can be easily removed for cleaning.
The Schoenauer magazine has disadvantages. It is much more costly to make than a staggered-column type because every part of the system has to be made for the specific cartridge for which the rifle is chambered. Once so made, it is not readily adaptable to cartridges with different dimensions.
Takedown and Assembly
Make sure chamber and magazine are empty. To remove the bolt, raise the bolt handle and pull it back and out while depressing the bolt-stop. To disassemble the bolt, grasp the bolt body in one hand and, with the other, rotate the cocking piece ¼-turn counterclockwise so it is against the bolt; depress the safety and swing it to the right. Turn the firing