the left (top) lug is partly slotted in front to allow passage of the ejector, this slot extending partly into the bolt-face recess.
7.7mm Japanese Arisaka Type 99 (1939) rifle, shown with the breech cover and monopod, but minus cleaning rod.
There is also an auxiliary lug (not a locking lug) just to the rear of the left (top) locking lug. This acts as an activator for the ejector, and as the bolt-stop lug when it engages with the bolt-stop when the bolt is opened. An inclined slot in the rear of this lug prevents the bolt hanging up on the ejector, and trips the ejector when the bolt is fully opened.
The bolt face is recessed to about the depth of the cartridge rim. Part of this rim recess is undercut to allow the cartridge head to move up and under the extractor hook when the cartridge is fed from the magazine, as in the Mauser 98 and Model 1903 Springfield actions. This prevents double loading, since any cartridge bolt-fed into the chamber from the magazine will be extracted and ejected upon opening the bolt, even though the bolt was not fully locked during this procedure. The lower left edge of the rim recess is slightly higher than the rest of the rim and is slightly undercut. This affords extra bearing surface for the cartridge rim, from the slight side pressure of the extractor, so that on opening the bolt the cartridge or cartridge case will remain in place until forced out by the ejector.
The extractor, of Mauser design, is a long one-piece spring affair held on the bolt body by a collar around the bolt. Longitudinal movement of the extractor is prevented by a lip under the front part of the extractor engaging in a groove in the front end of the bolt. The extractor is non-rotating; that is, while it does rotate on the bolt, it does not rotate in the receiver or on the cartridge.
The Type 38 action has the simplest safety and firing mechanism of any centerfire bolt action known to me. Not counting the trigger, sear parts, receiver or bolt, the firing and safety mechanism consists of only three parts. This design has its virtues and drawbacks, as we shall see, but it is a very reliable and effective arrangement for a military rifle.
The bolt body is drilled from the rear to accept the one-piece hollow striker (call it the firing pin if you like) with its integral firing-pin tip in front and its cocking cam (sear) on the rear. The coil mainspring fits into the hollow part of the striker. The third part of the mechanism is the safety, although it has several other functions.
The safety is a large one-piece affair comprised of a cap to which is permanently attached a stem projecting forward from its hollow center. This stem extends into the hollow striker to compress the mainspring.
7.7mm Japanese Arisaka Type 99 (1939) long rifle. This version of the Type 99 is relatively scarce.
The safety is held on the rear of the bolt by a lug inside of the cap engaging over a ridge on the outside rear of the bolt body. The safety can be quickly and easily removed from the bolt by pressing it forward and rotating it clockwise about one-quarter turn. The safety is linked to the striker by a small stud on the safety stem engaging in a matching groove milled inside the striker. The safety is linked with the receiver when it is engaged by a small stud on the outside of the safety cap engaging in an L-shaped groove in the bottom rear of the receiver. In all, there is a complicated hook-up between safety, striker and bolt, and also with the receiver when the safety is engaged, certainly the result of someone’s ingenuity. The lug on the outside of the safety cap, engaged in the groove in the receiver, prevents the safety from rotating when the bolt handle is raised or lowered. The rear surface of the cap-like safety is knurled in a circular pattern to prevent it twisting under thumb or palm pressure when it is engaged by pressing it forward and rotating it one-eighth turn clockwise, or disengaged by again pressing it forward and rotating it in the opposite direction. The safety can only be engaged when the striker is cocked, and when engaged it locks both the striker and the bolt. The outside edge of the safety cap is usually serrated and made with a small hump so located that it is up when the safety is engaged.
Type 2 (1942) Japanese Arisaka takedown paratrooper rifle.
Japanese Type 38 6.5mm Training rifle, this specimen with receiver and some of its action parts made of cast iron.
The trigger system follows the Mauser M93-96 design (later copied in the Pattern 14 and 1917 Enfield actions). It consists of a sear pivoted on a pin through a small lug on the bottom of the receiver. The sear projection on the rear of the sear protrudes through a hole in the receiver and engages the cocking cam on the striker when the bolt is closed. The striker is thus cocked on the forward or closing motion of the bolt. A pin riveted on the front of the sear projects upward through another hole in the receiver, which prevents the trigger being pulled to release the striker, except when the bolt handle is straight up, the bolt then entirely unlocked, or when the bolt handle is fully lowered and fully locked. In these positions two narrow grooves in the bolt body align with the pin. The sear spring is compressed over this pin between the sear and receiver. The trigger, which pivots in the sear on a rivet, has two humps where it contacts the bottom of the receiver and these humps provide the usual two-stage military trigger pull.
The striker can be lowered on closing the bolt as follows: push the bolt forward until the striker contacts the sear; pull the trigger to allow bolt and striker to be moved forward until the base of the bolt handle contacts the receiver; release the trigger; lower the bolt handle by striking it smartly with the palm of the hand. This should only be done on an empty chamber.
The bolt-stop and ejector assembly is built into a long narrow integral housing which projects from the left of the receiver bridge. The bolt-stop, of Mauser design, is held in this housing and pivots on a screw through the underside of the rear end of the housing. It is tensioned by a flat spring locked to the front end of the bolt-stop. The ejector, positioned in a slot in the center of the housing, pivots on a separate screw, also turned in through the underside of the housing. There is no ejector spring. The ejector is activated by action of the auxiliary bolt-stop lug on the bolt which, on opening the bolt, pivots the front end of the ejector to the right, in the groove provided for it in the bolt head.
An opening is milled into the bottom of the receiver for the magazine opening. Integral lips or cartridge-guide ribs at the top of the opening hold the cartridges in the magazine and guide them into the chamber. The magazine, a thin piece of sheet metal folded to form a box, is reinforced at each end with a heavier piece of metal welded in place.
The milled steel trigger guard is combined with a magazine plate which has an opening to surround the bottom of the separate magazine box. A milled steel floorplate covers this opening. A lip on the front of the floorplate, engaging a groove in the trigger plate and a latch arrangement built into the front part of the trigger guard bow, holds the floorplate in place. Depressing the latch in the guard bow releases the floorplate.
The ends of the W-shaped magazine follower-spring fit into mortises cut into the bottom of the steel follower and floorplate. The top surface of the follower has a rounded ridge on its left side which forces the cartridges to assume a staggered position when they are inserted into the magazine. The rear edge of the follower is square and, when the magazine is empty, the follower rises high enough to halt the forward motion of the bolt, indicating to the shooter that the magazine is empty.
The action is held in the stock by the two guard screws through the ends of the trigger guard and threading into the receiver. The front guard screw passes through an integral stud on the floorplate and threads
