The Fiat Revelli Machine Gun

Transcript

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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.
tion 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
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 ammuniLead photo, above: Classic left side
profile view of the Italian FIAT
Revelli Model 1914 water-cooled
machine gun.
Right: Right side view the Italian
FIAT Revelli Model 1914.
34
The Small Arms Review - Vol. 8 No. 11 - August, 2005
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
Left: Detail of the right side of the
FIAT Revelli. Note the water intake
cap on the top of the water jacket and
the two water input and outtake
valves on the bottom of the water
jacket. The forward valve is for water input and the rear valve is for
water and steam vapor output. The
two large vertical slots on the front
of the tripod head are for mounting
an armor plate. The hinged top ejector port cover is open.
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 watercooled 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.
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.
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
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
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
Right: The inspection plate has been
removed to expose the inner working mechanism of the gun. Note the
three position wedge lock adjustor
marked “MENO and PIU (minus
and plus). This enables the amount
of jamming effect of the wedge on
the moving parts to be increased or
decreased to ensure the smooth operation of the gun. The large friction lock handle can be seen on the
tripod head under the feedway and
the fine adjustment friction lock and
traverse stops can be seen at the rear
of the tripod head.
35
Right: The raised leaf sight ranges
from 200 to 2,000 meters. Note the
three position fire control selector
switch just above the thumb trigger
marked
“LENTA”
(slow),
“SICURA” (safe) and “RAPIDA”
(fast). The cocking handle with its
cross shape can also be seen directly
beneath the sight base. The cocking
handle is connected to the breechblock (bolt) and travels back the 51/4 inches to the buffer plate with
each shot. Not finger friendly.
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
Left: Operating end of the FIAT Revelli Model 1914 with the leaf
sight up, ejection port open, box magazine inserted and fire control selector switch set to full automatic. The two control knobs
for large and precise elevation movement can be seen attached to
the left rear leg elevating mechanism.
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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
Above: The FIAT Revelli wood ammunition box has compartments to hold eight
50-round box magazines for a total of 400 rounds. Also shown is the 100-round
box magazine used for anti-aircraft applications and the wood loading tool.
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
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
Right: Sectionalized drawings of the FIAT Revelli
Model 1914 machine gun.
The top drawing shows the
positions of the inner
mechanism with the cocking
handle/bolt in the rear position touching the recoil
buffer plate. The bottom
schematic shows the parts
with the bolt closed.
(Comando
Riparto
Mitraglieri “FIAT” Scuola
di Bresica, Istruzione per le
Compagnie Mitragliatrici
Mod. 1914 (Fiat). Volume
II. Brescia, 1917)
37
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 watercooled 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
Above: Completely stripped FIAT Revelli Model 1914 water-cooled machine gun showing all
breechblock (bolt). At
its component parts. (Comando Riparto Mitraglieri “FIAT” Scuola di Bresica, Istruzione per
this stage the movement
le Compagnie Mitragliatrici Mod. 1914 (Fiat). Volume II. Brescia, 1917)
of the breechblock relative to the sleeve is controlled by a wedge, which is capable of bearing against the latter at the shoulder, its backward action under its acquired morotation about a fixed axis at right angles forces the sleeve, together with the barrel, mentum. The wedge is maintained at its
to the axis of the bore. The rearward move- rearward. After a movement of about 4mm lowest position by its nose riding on the
ment of the breechblock causes the wedge on the part of the moving portions, the under surface of the breechblock. Hence,
to rotate to the rear. In so doing the wedge, wedge is entirely disengaged from the the sleeve cannot move forward until the
which passes through a slot in the sleeve, breechblock, which is now free to continue 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.
Left: Test firing the
FIAT Revelli M1914 machine gun. Note the assistant gunner turning
the water pump crank
handle, the pile of
ejected box magazines
and the quantity of the
top ejected empty brass
casings. (Metallurgica
Bresciana gia Tempini
Brescia. Mitragliatrice
Automatica “FIAT”)
38
Right: Detail drawing of the box
magazine indexing mechanism of the
FIAT Revelli Model 1914. (The Machine Gun, Volume IV, Parts X and
XI by Col. George M. Chinn. Prepared for the Bureau of Ordnance,
Department of the Navy, 1955)
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 100round 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
Left: An Italian Alpini (Alpine mountain troops) machine gun unit demonstrating how the FIAT Revelli
machine gun can be employed for offensive operations in World War I
using the backs of assistant gunners
as a makeshift shooting platform.
39
Left: Detail drawing of the operating principals of the wedge lock in
retarding the rearward movement
of the bolt in the FIAT Revelli Model
1914. (The Machine Gun, Volume
IV, Parts X and XI by Col. George
M. Chinn. Prepared for the Bureau
of Ordnance, Department of the
Navy, 1955)
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
FIAT Revelli Model 1914
Specifications
Caliber:
Muzzle velocity:
Weight of gun w/o water:
Method of cooling:
Length of gun:
Principle of operation:
Type of fire:
Rate of fire, cyclic:
Rate of fire, practical:
Length of barrel:
Rifling:
Feeding method:
Magazine capacity:
Front sight:
Sight radius:
Rear sight:
Sight graduation:
Mounting:
Tripod weight:
Tripod elevation:
Tripod Traverse:
40
6.5mm (.256 caliber)
2,450 feet per second
37.5 pounds
Water and water pump holding 2-1/2 gallons
40.5 inches
Short recoil, delayed blow-back with
rotary wedge
Semiautomatic or full automatic
500 rounds per minute
250 rounds per minute
23.5 inches
4 grooves, uniform, right hand twist
Compartmentalized box magazine
50 and 100 rounds
Fixed taperpost
35 inches
Leaf, step elevating “V” notch
200 to 2,000 meters
Tripod
49.5 pounds
25 degrees
30 degrees
• 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.
Below: Fascist era armband for the
National Association of Machine
Gunners features the FIAT Revelli
machine gun to the center. The red
with three white stripe collar insignia to the left denotes FIAT Divisions, while the blue with three
white stripes collar insignia on the
right denotes St. Etienne Divisions.
Above: Transporting the gun, tripod and ammunition boxes using shoulder
and pack board carriers. (Metallurgica Bresciana gia Tempini Brescia.
Mitragliatrice Automatica “FIAT”)
Above: Ten members of the 8th machine gun company based in Milan, June
1917, pose with their FIAT Revelli Model 1914 machine gun.
41

The Fiat Revelli Machine Gun

Transcript

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