The rifle has a breech mechanism of the bolt type, the bolt being locked by a turning movement, which causes lugs on the bolt to engage in recesses just in rear of the chamber. There is a camming action of the locking lugs to seat cartridges firmly, which continues throughout the locking action. To preclude the possibility of the bolt's unlocking under powder pressure, a safety stud is mounted on the sear and rises, as the trigger is pulled, to lock the bolt against turning. This serves also to preclude pulling of the trigger unless the bolt is fully locked.

The magazine is, directly beneath the bolt and is loaded from the top from a clip of five cartridges while the bolt is retracted. It contains a spring-actuated follower, above which the cartridges arrange themselves in laterally staggered relation.

This follower feeds the top cartridge up into the path of the bolt when the latter is retracted, a ramp serving to guide the nose of the bullet upward and into the chamber as the cartridge is forced forward on the succeeding forward movement of the bolt.

The ejector is of the spring-actuated type and operates through a slot in one of the locking lugs at the limit of rearward movement of the bolt. The ejector spring is integral with the ejector.

The firing pin has no cocking knob and can not be cocked except by actuation of the bolt. It is half cocked by the unlocking movement of the Bolt, a cam and half-cock notch being provided on the rear end of the bolt to engage a lug on the cocking piece and. perform this function. The sear notch of the cocking piece engages the sear nose in the closing movement of the bolt, so that the piece is cocked by the act of closing the bolt. The locking of the bolt moves the half-cocking cam out of the path of the lug on the cocking piece. This arrangement precludes the closing of the bolt upon a cartridge with the point of the striker protruding through the end of the bolt.

There is no magazine cut-off. The follower rises and locks the bolt open when the magazine is empty, and to prevent this, so that the rifle may be used as a single loader or in simulated fire drill, an accessory, called the follower depressor, is provided.

The safety lock consists of an eccentric detent which engages a notch in the cocking-piece lug and lifts the sear notch off the sear nose and a sliding plunger, which simultaneously enters a hole in the bolt handle and locks the bolt closed. These parts are operated by a thumb piece, mounted at the right, just in rear of the bolt handle, in position for convenient actuation by the right thumb.

The bolt stop engages one of the locking lugs. It is spring held, and may be retracted to permit withdrawal of the bolt at the rear. The firing pin and sleeve can be removed from the bolt and completely dismounted without the use of tools.

The front sight is protected by lateral wing guards, and may be adjusted laterally during assembly. Height adjustment is secured by the interchange of sights of different heights.

The rear sight is protected by lateral wing guards. The battle sight is of the peep type and, being formed at the lower end of the leaf, rises to position as the leaf is laid. The leaf carries a peep sight, on a slide which moves vertically, and hence makes no correction for drift. There is no windage adjustment.

The sling, stacking swivel, and accessories are of familiar types and need no preliminary description.

The ammunition is the U.S. Caliber.30 Rifle Cartridge, Model of 1906, five cartridges in a clip. These are the same cartridge and clip as are used in the U. S. Rifle, Caliber .30, Model of 1903.

The rifle is shown in plan in Fig. 1 and in elevation in Fig. 2.

The BARREL A, with the spline seat B, is shown in Fig. 3. It is 26.05 inches in length, and the rifling consists of 5 grooves approximately 0.005 inch deep. The lands and grooves are equal width. The twist is left-hand and uniform, 1 turn in 10 inches.

The muzzle is rounded to protect the rifling. The tenon C at the rear is square-threaded for the purpose of securing the receiver to the barrel. A shoulder D is provides to form a seating for the receiver.

The front sight carrier is held in position by means of the SPLINE F, illustrated in. detail in Figs. 6 and 7, which are top and side views. This spline is seated and fits closely in the spline seat in the top of the barrel (see B, Fig. 3), and is thus held against movement in any direction. It fits in a keyway G in the collar A of the front sight

carrier and is locked to said carrier by the FRONT SIGHT CARRIER PIN H (see Fig. 8), which passes through a transverse hole J in the front sight carrier and engages a notch K in the top of the spline F.