FIAT-Revelli M1914 and M1914/35 machine gun (Italy)
FIAT-Revelli M1914 machine gun
FIAT-Revelli M1914/35 machine gun
Multi-column magazine for FIAT-Revelli M1914 machine gun
M1914
M1914/35
Caliber
6.5x51 M91
8x59 M35
Weight
17 kg (gun less water) +
22.4 kg (tripod)
18.1 kg (gun body) + 23 kg
(tripod)
Length
1180 mm
1270 mm
Barrel length
654 mm
653 mm
Feed
50-round
multi-compartment magazine
belt, 50 rounds
Rate of fire
400 rounds per
minute
500 rounds per
minute
After much experimenting and tests with domestic and imported
machine guns, after the start of the Great War the Italian army adopted
domestic machine gun, the Fiat-Revelli M1914. It was officially known
as the Mitragliatrice
M1914- (machine gun, model of 1914). Its basic design was
the brain-child of Bethel Abiel Revelli, a Captain in the Italian army,
who had already designed a semi-automatic pistol adopted by Italian
military.
In his machine gun Revelli employed the same retarded blowback system
with a movable barrel that he also used for his pistols (Glisenti M1910
and Brixia M1912). Revelli patented his first machine gun ideas in
1908, and in 1913 a medium machine gun of his design was more or less
successfully tested by the Italian army. This weapon had some other
peculiar features, such as the unusual feed system, which is quite hard
to classify. It could be described as multi-compartment box magazine,
which was moved sideways (harmonica-style) once the previous
compartment had been emptied. The downsides to this set-up were the
heavy weight of the magazine and its tendency to collect dust, dirt,
snow and other battlefield debris because of its open design.
Obviously, all this debris was then moved along with the cartridges
into the gun. Another feature, a top-mounted crescent-shaped charging
handle which oscillated during firing above the top of receiver, gave
this gun the nick-name of “knuckleduster”.
During the early 1930s Italian army decided that the 6.5mm ammunition
lacked the range and striking power desirable in a medium machine gun.
A series of trials was organized to select an improved round of
ammunition, which cumulated in the adoption of the 8x59 M35 cartridge,
also known as the 8mm Breda. This was a powerful round, which
outclassed the 6.5x52 M91 by a wide margin. The first gun to be
chambered for this round was the heavily modified FIAT-Revelli, which
in the course of development lost its harmonica-type magazine system,
integral oiler (later re-installed due to poor functioning of the gun
without oiler) and water-cooling jacket. Its new feed system comprised
a removable belt-feed unit (using non-desintegrating steel belts), and
new air-cooled barrels with fluted chambers were made quick-detachable.
Most of the 8mm FIAT guns, designated as M1914/35, were converted from
older M1914 guns, but at least some were also newly manufactured in 8mm
caliber. While it served through World War 2, it was hardly an
improvement over the M1914 and disappeared immediately afterwards.
The FIAT-Revelli M1914 machine gun is a water-cooled, retarded-blowback
operated weapon that fires from a closed bolt. Its action employs a
recoiling barrel (with a relatively short recoil stroke), and a
rectangular, longitudinally-sliding bolt mounted inside the barrel
extension. The bolt and barrel are connected by a pivoting wedge,
located in the receiver. The wedge is allowed to rotate back and forth
around the axis located below the moving parts. When the parts are in
battery, the top part of the wedge passes through a small opening in
the bottom of the barrel extension and enters a recess cut on the
underside of the bolt. Upon discharge, the gas pressure forces the bolt
rearwards and its movement rotates the wedge back. This rotation also
carries the barrel extension and barrel along in the recoil movement,
although because of slightly different leverage barrel recoil velocity
is lower that than of the bolt. This initially adds the mass of the
barrel group to the mass of the otherwise unlocked bolt while pressure
in the barrel is still high. Once the wedge has rotated back enough to
release the bolt, the barrel is stopped and the bolt is free to
continue rearwards under the residual gas pressure and accumulated
inertia. The axis of the wedge is eccentric, so the exact position of
the wedge in relation to the barrel extension and bolt can be adjusted
for proper functioning. This can be done after opening the right side
plate of the receiver.
The rear part of the bolt in full recoil projects from the receiver
above the top cover, and is fitted with a T-shaped cocking handle. At
the end of the recoil cycle, the cocking handle strikes the recoil pad
/ buffer located above the receiver cover and between the spade grips.
This machine gun fires from a closed bolt and is therefore fitted with
a separate striker firing mechanism. The rear part of the striker
projects behind the cocking handle, so the operator can visually check
if the gun is cocked, or even re-cock the gun manually. The firing
controls include a thumb-trigger located between the spade grips at the
rear of receiver, and a manual safety/selector lever above the trigger.
The gun fires in automatic or single shot modes, with the sear being
tripped in automatic mode by the retarding wedge once it rotates to its
forwardmost position during counter-recoil cycle. The mode of fire is
selected by the position of the safety switch.
The feed system is most unusual, as it uses a horizontally-sliding
block of integrally connected single-stack box magazines, located
side-to-side. The feeding unit consists of 10 compartments, each of
these holding five rounds under the pressure of individual springs. A
fresh “magazine” is inserted into the large receiver aperture from the
left, until the first compartment is in line with the barrel. Fresh
cartridges are stripped by the bolt from the top of the compartment
until last one is fed. When this happens, a protruding lip, formed at
the rear of the compartment’s cartridge follower, trips the internal
lever which releases a spring-loaded indexing mechanism that moves the
feed unit across one step to the right, until the next full compartment
is positioned in line with the barrel. The spring of the indexing
mechanism is then re-cocked automatically by the movement of the barrel
extension. Once all compartments in the feed unit are expelled, the
unit is ejected from the gun automatically. Empty cases are ejected
upwards through an aperture in the top of receiver. This aperture is
fitted with a manually-opening dust cover. It is interesting to note
that while this magazine unit seems to provide quick reloading from
standard rifle stripper clips, in fact this was not possible. The
Italians at the time used Mannlicher-type en-block clips in their
Carcano rifles, and, furthermore, those clips held six cartridges
rather than the five needed to fill one compartment in Revelli magazine.
The standard mounting for Revelli machine gun was a solid tripod with
tubular legs, fitted with traverse and elevation mechanism.