Bolt Action Rifles. Wayne Zwoll

double interrupted rings engaging the two parts. Ordnance specifications called for a firing pin protrusion of not over .068”, and not under .058” minimum, and a firing-pin hole no larger than .085”.

      U.S. Model 1917 Enfield action.

      Two gas-escape holes in the front of the bolt direct escaping gases into the left side locking raceway.

      Primary striker cocking occurs on raising the bolt handle, when the forward end of the cocking piece engages a shallow cam in the rear of the bolt. Full cocking takes place on the forward travel and closing of the bolt, after it has been fully opened. The shallow cam and the short initial rearward movement given to the striker when the bolt handle is raised are safety features which prevent the action from firing a cartridge unless the bolt is locked sufficiently to hold it closed. The cocking piece is engaged when the bolt is open, and also positions and prevents rotation of the bolt sleeve.

      The rugged rotary safety, just to the rear of the bolt handle, is built into the tang of the receiver. With the action closed and cocked, tipping the safety lever back locks the striker and bolt. The striker is locked back, and pulled back off the sear, by the end of the safety system engaging a notch cut into the side of the cocking piece. The bolt is locked closed by a pin pushed forward by the safety into a hole in the base of the bolt handle.

      The trigger is a common double-stage military type. The long first stage of the pull moves the sear almost all the way off the cocking piece, the final short pull fully releasing it. An added safety feature, built into the sear, is a pin projecting upward through a hole in the receiver. Only when the bolt is fully closed, which places a notch cut into the body of the bolt directly over the pin, can the trigger be pulled to release the striker.

      The action is held in the stock by two guard screws, one at either end of the action, passing through holes in the trigger guard plate. Stock bushings, through which the guard screws pass, provide proper spacing between trigger guard and receiver. The magazine box is a separate unit fabricated by riveting two flat thin pieces of sheet steel, which form the sides, to the thicker ends. The top of the front end projects up into the magazine-opening well to become part of the loading ramp. The magazine box is securely positioned between the trigger guard and receiver, and is partly recessed into these parts. The magazine-well opening in the bottom of the receiver is milled to leave lips for holding the cartridges in place in the magazine. The milled steel floorplate, detachable from the trigger guard, is held in place by projecting lips engaging recesses in the trigger guard, and is secured by a small spring-loaded latch in the guard just to the rear of the magazine box opening. Depressing this latch with a pointed tool, through a hole in the rear of the floorplate, allows the latter to be moved back and released.

      Model 1917 Enfield action open.

      Top side view of Model 1917 Enfield action.

      Left side view of Model 1917 Enfield action.

      The trigger-guard bow is egg shaped, the opening larger in front. The face of the curved trigger is grooved. The milled magazine follower and the follower spring are the conventional Mauser type. The magazine holds six cartridges in a staggered column. When the magazine is empty the follower rises in front of the bolt, when the action is opened, preventing the bolt from being closed. All action parts are made of steel; there are no stampings.

      Disassembly

      To remove the bolt, grasp the front edge of the bolt-stop with the thumb, swing it outward, raise the bolt handle and pull the bolt out. To remove the floorplate, insert a pointed tool into the hole in the rear of the plate, depress the tool while at same time pulling it to the rear. This releases the floorplate, follower spring and follower.

      To remove the barrel and action from the stock, first remove the upper and middle barrel bands and handguard, then remove the front and rear guard screws. Lift the barrel and receiver from stock, then pull out the trigger guard. The barrel is threaded very tightly into the receiver and no attempt should be made to remove it unless proper equipment is on hand.

      Disassemble the bolt by grasping the bolt body in the right hand and, with a tool (such as a small screwdriver) in the other hand, pull the cocking piece back, rotating it and the bolt sleeve counterclockwise about one-half turn. Unscrew the bolt sleeve further until the cocking piece drops down, then repeat the process until the entire striker assembly is removed.

      To disassemble the striker mechanism, place the firing pin tip on a hard surface and grasp the bolt sleeve very firmly; pull the bolt sleeve down as far as it will go, then turn the cocking piece one-quarter turn in either direction and lift it off.

      To remove the extractor, turn it on the bolt to cover the gas-escape vents, then push it forward to disengage it from the extractor collar. The collar can then be spread apart and removed from the bolt.

      Turn out the bolt-stop screw and remove the bolt-stop assembly. Push out the sear pin and remove the trigger/sear assembly. With a small screwdriver turn out the safety-lock holder screw and remove the holder. Swing the safety back, then pull the safety out, after which the safety lock plunger and spring can be removed. Reassemble in reverse order. In reassembling the safety, first insert the safety lock plunger spring, then the lock plunger into the hole in the receiver. Using a screwdriver, turn the lock plunger so its V surface is in line with the hole, then push the lock plunger forward and, at the same time, firmly grasp the front end of the plunger with a pliers. While holding it, remove the screwdriver, insert the safety and release the pliers.

      To assemble the bolt-stop, with the bolt forward and the handle raised, lay the action on a bench with the left side up. Position the bolt-stop spring rest on the receiver. Insert the ejector in the bolt-stop then insert the bolt-stop spring, pressing the hooked end of this spring into the front end of the bolt-stop until it is level with the latter. Position the assembled bolt-stop in place on the receiver, turning the rest to align the groove for the bolt-stop spring. Using a screwdriver handle or similar tool, firmly press the rear end of the bolt-stop against the receiver, then insert and turn in the bolt-stop screw.

      Close-up of rear part of Model 1917 Enfield action showing how bolt handle forms safety lug by engaging a deep notch in the receiver (arrow).

      Strong and Weak Points

      The only really weak part in this action is the ejector. It is a leaf spring which usually breaks off and leaves the ejector useless.

      Not a design fault, but rather a construction fault, is that some of the 1917 receivers develop hairline cracks. By no means a common occurrence, it is common enough to be of some concern to owners of these actions. The cracks usually appear some place around the receiver ring, often starting at the front edge of the receiver and extending rearward in an erratic pattern. Although Winchester and Remington receivers have been found with cracks, the Eddystone-made receivers are by far the most frequent offenders. It is believed that many of these receivers were given a faulty heat-treatment, the metal thereby becoming too hard and brittle. Not easily spotted, the cracks are most often detected when the action is polished and reblued. They can often be detected with the naked eye, or by carefully examining the receiver ring with a hand magnifier.

      Another good way to detect cracks is to dunk the receiver in gasoline for a moment. If a crack (or cracks) is present, the gasoline will seep from it after the rest of the receiver has dried. Cracked receivers are generally not repairable, so they should not be used.

      While cracks may well be the result of improper heat treatment, they’re most frequently found on receivers from which the original barrel has been removed. Barrels were fitted