The Machine Gun

lubrication of each round was an integral part of the receiver.

There being no immediate prospect of war, nothing was done about the manufacture of the weapon except for the few handmade working models produced locally by the inventor. Revelli early became associated with the Fiat automobile plant located at Turin, Italy, and it was this company that first became interested enough to make a few demonstration models. There is an official record of the submission of a Revelli machine gun to an United States Army board in 1911, and in 1913 a test report by the Italian Government stated the weapon was suitable for service use. The gun employed at the time a 100-round magazine in lien of the f>()-round device. While it functioned satisfactorily, it was thought to exert too much weight at the left side of the mechanism when first positioned in the feedway, and restoration of the smaller box was recommended.

Italy's entry into World War I gave Revelli and his theories of machine gun construction a great opportunity, of which he took full advantage. This water-cooled model was turned out in great numbers by the Fiat Co. along with many other designs by this creator of Italian machine guns. The main Italian automatic infantry weapons stemmed from the earlier trial and development projects initiated by Fiat. The tests had been personally conducted by Revelli, who by this time held a captain's commission in recognition of his being instrumental in furnishing Italy with a machine gun of native origin.

To fire the weapon, the selector switch is moved from "Sicura" (safe) to "Rapido" (fast, or full automutic) and the trigger button pushed forward, bringing the sear out of contact with the bolt. This permits the striker to be thrust forward under compression of its driving spring, sending the firing pin into the primer to explode the powder charge in the cartridge. As the bullet travels down the barrel, the rearward action of the gas pressure against the cartridge base pushes with corresponding force against the brccch-block.

The barrel sleeve and breechblock move back locked together for a distance of a half inch. The barrel extension is stopped at this point by a cross bar fixed to the receiver. Unlocking now begins by means of a wedge which starts to rotate about a fixed axis at right angles with the bore. As the breechblock goes back, the wedge is forced to swing to the rear.

The wedge passes through a slot in the under side of the sleeve at an angle that cams the sleeve and barrel to the rear. This slight delay permits the bullet to clear the bore and the gas pressure to drop to a safe operating limit. At this point the wedge is moved entirely out ol engagement with the breechblock. The latter travels backward under the momentum imparted to it by the blow-back gases. A nose on the under side of the breechblock holds the wedge down for the remainder of the rearward action. During the retracting movement the extractor guides the empty cartridge case out of the chamber, holding it to the face of the bolt until its base collides with the ejector which hurls it through the top opening in the gun. As each magazine compartment is emptied, the projecting tip at the rear of the compartment raises a pawl which permits the feed ratchet arm to index the next compartment of the magazine.

A strong coil spring, which is extended during the rearward motion, provides energy for return. It is attached to a connecting rod, one end of which hooks to a claw on the bottom of the rotating wedge and the other end to an adjustable spring fastened to the frame of the gun.

As the breech block continues traveling to the rear, its spring is compressed against the head of the receiver. When the force of the recoiling action has been dissipated, the spring attached to one end of the frame in the lower part of the receiver exerts tension on the clamp at the bottom of the wedge. The sleeve and barrel are drawn forward as the firing-pin spring acts to force the breechblock forward at the same time that the sear holds the striker back out of engagement.

In counterrecoil the breechblock strips the cartridge from the magazine, then positions, and finally chambers it. The operating parts are now in battery, ready for the release of the firing pin, which will start the cycle all over again.

An unusual feature of the Revelli is that the cocking handle is incorporated in the rear portion of the bolt, and protrudes unhoused from the rear of the gun. It is shaped like a cross pet-

Was this article helpful?

0 0

Post a comment