- Not to be confused with the Beretta M31 pistol.
The Beretta Mod. 31 is an Italian prototype self-loading rifle.
Designed by Tullio Marengoni in 1931, the rifle was developed as a response to the Italian Army looking for a self-loading rifle. The rifle was redeveloped into the Beretta Mod. 37 six years later due to the Army wanting to use 7.35×51mm Carcano instead as they felt that 6.5mm rounds lacked stopping power.
One rifle, serial number 1, is currently held in Beretta's reference collection.
The Mod. 31 was a recoil-operated self-loading rifle with a rotating bolt; operation is very similar to that of the Johnson rifle. The Mod. 31's rear sight was identical to that of early Carcano rifles. When the rifle fires, the barrel recoils backwards, unlocking the bolt, allowing it to travel backwards and cycle the gun.
The rifle has a finned barrel and what appears to be a brass sleeve that the barrel recoils back and forth inside of. A peculiar-shaped cutout is cut out into the receiver; this cutout is supposed to be there and acts as a cavity for the front sight post to rest inside of when not in use. A bolt release is present as a very tiny button located at the rear of the receiver.
The rifle feeds from standard six-round Carcano en bloc clips fed from the bottom of the rifle; opening a hatch on the bottom of the internal magazine allows one to load a clip inside à la RSC Mle 1917. The weapon's hammer is very strangely shaped; it has a large curved surface due to the internals of the gun, with the hammer missing the main spring and just hitting the bottom of the firing pin.
The weapon's bolt is a two-piece bolt of sorts as it disassembles into two pieces; the actual bolt and the large firing pin housing which is usually under spring tension via a spring located in the bolt housing. The firing pin housing is hollow and has a large lug on the outside which serves two purposes; to guide the firing pin via a track cut into the bolt housing and serves as the surface which the oddly-shaped hammer hits to fire the weapon.
The firing pin spring also has two purposes; not only does it return the firing pin to its normal position after firing, it also provides the motive force to unlock the bolt. A dust cover is also present on the weapon which opens up when the rifle is charged. Disassembly of the weapon is very simple; engage the safety, screw off the rear receiver cap, push the ejector assembly in and one can pull all the internal components of the weapon out.