ITALIAN FIAT REVELLI MODEL 1914

By Robert G. Segel

Italy was the first country in the world to officially adopt the Maxim machine gun after the La Spezia trial of 1887, ultimately purchasing several hundred of the 1901 “New Pattern” Maxims to equip its army. Nevertheless, under the auspices of national pride, the Italian War Ministry was interested in encouraging a domestic machine gun development program; a machine gun designed and built in Italy.

Perino Machine Gun

In 1901, Giuseppe Perino, officer in charge of the Italian artillery factory in Rome, patented and built a recoil and gas operated machine gun that had many advanced features for its time, including a unique feed system. This feed system consisted of a metal tray holding twenty-five rounds and was fed into the gun from the left. There was no ejection port as the expended cartridges were replaced in the tray. An ammunition box was attached to the receiver and held five of these ammunition trays. The gun fed the trays one at a time from the bottom making it easy to keep full by the assistant gunner by laying loaded trays on top of the stack. The Italian War Ministry determined that it was an excellent weapon and, for reasons known only to the Italian government, designated the Perino as Top Secret and Confidential. Only a few were built for experimental and testing purposes until the government felt it was improved enough to compete with other well-known made guns on the world market.

In 1908, Italy conducted a secret trial comparing the Perino with the Maxim. The Perino fared well but further changes were deemed necessary resulting in a 1908 model; a refined version of the original design. Shortly thereafter, a 1910 model was developed with more changes. Yet the Italian War Ministry, in its desire to keep the gun a secret, continued to purchase and equip its army with Maxims while still trying to perfect the Perino. By maintaining the ultra-secret security measures, the Perino was never tested in open trials which actually retarded the development of the weapon. Having been in development for over ten years without any proof of its reliability or efficiency, it was considered outmoded before it had been adequately proved.

FIAT Revelli Machine Gun

In 1908, a young Italian inventor from Rome by the name of Captain Bethel Abiel Revelli, applied for his first patent on machine guns. The first of many, Revelli’s name would ultimately become synonymous with Italian automatic weapon design and would become a high ranking military officer in the Italian army.

Revelli had already caught the attention of the Italian army when he earlier designed (circa 1906) a swinging wedge to lock the breech of a pistol that would become the basis of the Glisenti Model 1910 semiautomatic pistol. The Glisenti M1910 became the standard Italian side-arm for non-commissioned officers and enlisted men of machine gun and artillery detachments until replaced by the Beretta Model 34 in 1934. In 1908, Revelli used a similar system as he began work on his water-cooled machine gun using a delayed blowback operating system. He additionally designed a unique feed system using a metal cage containing the cartridges rather than a belt or feed strip system. The gun was chambered in the standard 6.5mm (.256 caliber) Italian service cartridge.

Select-fire

One of the interesting aspects of his design was that the gun is select-fire. There is a three-position lever located directly above the thumb trigger that served as the safety and fire control selector. To the left is marked “LENTA” (slow) that enabled the weapon to fire in single shot mode. Vertically in the center is marked “SICURA” (safe) and is the safety setting for the weapon. To the right is marked “RAPIDA” (fast) allowing the weapon to fire until the trigger is released or the ammunition is expended. (While it is logical to have the different firing modes to each side with the safety setting in the center, the lever easily can be bumped or pushed to one side rendering the gun in an unsafe condition; resulting in an accidental discharge if the trigger is pushed by accident.)

Cocking Handle

The cocking handle is designed in the shape of a cross. This allows the cocking handle to be grasped on both sides with the fingers of one hand and drawn to the rear. It is incorporated in the rear portion of the bolt and protrudes exposed from the rear of the gun along the topmost portion of the receiver. The cocking handle recoils with the bolt striking a buffer plate located directly in front of the top portion of the spade grips. With a cyclic rate of approximately 500 rounds per minute, the exposed cocking handle, traveling 5-1/4 inches back and forth, proved hazardous to any finger that strayed into its operating path.

Water-Cooling System

Revelli used a water cooling system that further enhanced the method that was typical of water-cooled machine guns of that era. Maxim, Vickers, Schwarzlose and Browning used a steam condensing tube within the water jacket to allow the steam vapor pressure build-up to escape through a steam condensing port. Revelli expanded on that by additionally incorporating a water replenishment system in his design. As in the others, water is introduced into the water jacket by a filling port located at the top of the rear of the water jacket just in front of the trunnion. On the Revelli design, the steam condensing port is the rear of two valve fittings located beneath the water jacket directly in front of the trunnion. A hose is attached to this fitting to redirect the steam vapor. The forward valve allowed water to be replenished into the water jacket via a hose connected to a manually operated water pump. This operation was accomplished by an assistant gunner turning the pump handle as needed on the water can.

Cartridge Oiling System

It should be noted that almost every reference book discussing the FIAT Revelli Model 1914 mentions that since the gun was a delayed blow-back weapon, which resulted in violent extraction of the fired cartridge case, an oil pump is incorporated within the receiver to lubricate the cartridges prior to chambering. This is not true. The FIAT Revelli Model 1914 does not have, nor did it ever have, a cartridge oiling system. A later version in the 1930’s briefly incorporated such a system but was quickly replaced with a barrel with a fluted chamber to ease extraction.

Tripod

The tripod is of a standard configuration with two front legs that may be folded to the rear for transportation purposes. There is no accommodation for a seat to be attached to the rear leg. The tripod head contains a dove-tail mounting bracket that corresponds to a matching mount on the bottom of the gun directly under the feed way. The gun is placed on the mount by sliding the gun rearward into the corresponding dove-tail grooves. To the rear of the tripod head is a spring loaded stud that slips into a hole located approximately mid way underneath the bottom of the receiver. This locks the gun in position on the tripod head and prevents any movement to the front or rear.

There is a large friction handle on the right side of the tripod head that allows for large traversing movement. For more precise traversing movement, another friction lock is located at the rear of the tripod head that allows more accurate traversing movement along an arced path with adjustable traverse stops.

Elevation is controlled by two knobs located on the left side of the rear leg attached to the elevation gear. The upper knob frees or locks the toothed elevation arc for large elevation or depression adjustments. The lower knob provides for finer elevation or depression correction.

World War I

Revelli spent a number of years perfecting his machine gun design and worked with the FIAT (Fabricca Italia Automobiles Torino) automobile company, who built his prototypes, in Turin, Italy. The Italian War Ministry gave the gun frequent trials where the gun performed well. But, the government was indecisive and no further development was encouraged. World War I changed all that.

Italy, like many countries that purchased machine guns on the world market, suddenly found themselves without a reliable source of foreign manufactured arms. Sources quickly dried up for Maxim, Vickers, St. Etienne and Colt guns as they were all desperately being used by the warring factions. Italy realized that, (1) Revelli’s machine gun had performed well in their trials and, (2) FIAT had the capacity and machinery to immediately begin production with the ability to expand production as needed. Thus, Revelli’s machine gun was quickly approved and adopted as the FIAT Revelli Modello 1914 and, without delay, put into production. The FIAT Revelli M1914 remained in front line service for almost thirty years until Italy capitulated in 1943 in World War II. In a modernization program in 1935, the water-cooled jacket was removed in favor of air cooling.

Function of Revelli’s Wedge Lock

The FIAT Revelli Model 1914 operates on a delayed blowback principal using Revelli’s wedge lock design. On firing, the pressure of the propellant gases, acting through the base of the cartridge imparts a rearward movement to the breechblock (bolt). At this stage the movement of the breechblock relative to the sleeve is controlled by a wedge, which is capable of rotation about a fixed axis at right angles to the axis of the bore. The rearward movement of the breechblock causes the wedge to rotate to the rear. In so doing the wedge, which passes through a slot in the sleeve, bearing against the latter at the shoulder, forces the sleeve, together with the barrel, rearward. After a movement of about 4mm on the part of the moving portions, the wedge is entirely disengaged from the breechblock, which is now free to continue its backward action under its acquired momentum. The wedge is maintained at its lowest position by its nose riding on the under surface of the breechblock. Hence, the sleeve cannot move forward until the recess in the breechblock returns to within about 4mm of it initial position.

The axis of the wedge is eccentric, and can be adjusted in one of three fixed positions in its bearings. This enables the amount of jamming effect of the wedge on the moving parts to be increased or decreased to ensure the smooth working of the gun.

The return of the moving parts to the firing position is caused by a strong spring operating through a connecting rod, one end of which is hooked to a claw on the bottom of the wedge, the other end being connected to an adjustable spring, which, in its turn, is attached to the frame of the gun.

The claw does not assist in the locking of the action, but is the medium by which automatic firing is controlled.

Box Magazine

The FIAT Revelli Model 1914 uses a unique box magazine sometimes referred to as a “mousetrap action” or a “squirrel cage.” The gun primarily used a box magazine containing 50 rounds though a 100-round box magazine was employed for anti-aircraft use. Both box magazines are identical except for the number of cartridges used. The 50 round box magazine is small and compact and can be quickly inserted into the left side of the gun.

The 50-round box magazine is actually ten separate 5-round magazines contained within one box. The magazine may be loaded in one of two ways: individually loading a round in a single column at a time, or by groups of five across the top using a special wood magazine loading tool.

To load one column at a time, a small metal protrusion attached to the magazine follower in each column section is depressed with the thumb of the left hand which is also holding the magazine box. The base of the cartridge is inserted and forced down under the cartridge retaining lips with the right hand. They are then slid back to be seated against the rear of the box. Five cartridges are then fed into each of the magazine columns one at a time.

To load the magazine using the wood loading tool, five cartridges are placed on top of five magazine followers to the front of the cartridge retaining lips. Using the five section wood loading tool, align and place the loading tool on top of the five cartridges. Press down to the rear and slide the five cartridges under the cartridge retaining lips and seat to the rear.

The loaded magazine is inserted in guides in the feedway on the left-hand side of the gun. As each cartridge in the column is chambered, the compartment spring forces the next cartridge upward, ready to be chambered by the forward movement of the bolt. When the fifth and last cartridge in the compartment has been fired, the small metal protrusion attached to the follower in the rear automatically engages a trip lever pawl that indexes the magazine one column to the right; where the feeding process is repeated. When all ten magazine columns have been indexed to the right and the magazine is empty, it is ejected from the feedway on the right side of the gun. The magazine indexing pawl may be disengaged to allow removal of a partially expended magazine. The indexing pawl disengaging lever is located on the bottom of the receiver directly behind the feedway.

Operation

• Turn the fire control selector switch, located at the rear of the gun just above the thumb trigger, straight up into the vertical position to the “Secura” (safe) setting.
• Insert a loaded magazine into the guides in the feedway on the left hand side of the gun and push to the right until the feed indexing pawl engages the box magazine.
• Open the hinged ejection port cover located on the top of the receiver directly above the feedway. (Empty cartridges are ejected out through the top of the gun and deflect to the right.)
• With the fingers of the right hand, grasp the cross arms of the cocking handle and pull straight to the rear. This compresses the main spring. Release the cocking handle and the breechblock (bolt) will travel forward, strip a cartridge from the box magazine and chamber it while connecting the firing mechanism.
• Turn the fire control selector switch to the left (Lento) for single shot or to the right (Rapido) for full automatic.
• Grasp the two spade grip traversing handles with each hand and press the thumb trigger forward to fire the gun.

Field Stripping the FIAT Revelli Model 1914

• A large pin at the rear of the receiver locks the spade grip traversing handles and trigger mechanism to the receiver. Pull the pin out to the left and drop the handles down to a horizontal position.
• Pull out and back on the spring held knob on the right hand side of the gun directly below the cocking handle. Slide the inspection plate in the guide to the rear and out of the gun. This exposes all the internal operating mechanisms, except for the breechblock (bolt), for inspection and adjustment.
• Press the spring release catch on the receiver lock pin, located just below the rear sight base and which passes through the gun. Pull out and remove from the right hand side.
• The cocking handle and breechblock, complete with recoil spring and firing pin, may now be drawn to the rear and out of the gun.
• Unscrew the firing pin from the breechblock and separate.
• This completes the basic field stripping of the weapon. Reassembly is in the reverse order.