Browning M1917A1
machine gun, right side, on M1917 tripod
Colt MG38 machine gun,
an commercial version of the M1917 of inter-war manufacture, on Colt
tripod
Polish-made unlicensed version of the Browning water-cooled machine gun, the
Wz.1930 in 7.92x57 Mauser caliber
Swedish-made 8x63 licensed version of the Browning water-cooled machine gun, the
Ksp-36, in AA modification
Browning M1919A2
machine gun, as used by US Cavalry after WW1
Browning M1919A4 machine gun
on M2 tripod, standard MG of US armed forces through the WW2 and Korea,
right side
Browning M1919A4, left side
Browning M1919A6 light machine
gun
Diagram that
explains diferences between M1919A4 and M1919A6
Belgian-made licensed version of the Browning air-cooled machine gun, the FN-30
(post-WW2 manufacture)
Illustration of the
Browning locking system as used in M1917 and M1919 machine guns.
M1917A1
M1919A4
M1919A6
Caliber
.30-06 / 7.62x63
Weight
14.8 kg gun body + 3.3 kg water + 24
kg M1917 tripod
14.1 kg gun body + 6.4 kgM2 tripod
14.7 kg gun with shoulder
stock and bipod
Length
981 mm
1044 mm
826 mm
Barrel length
607 mm
610 mm
610 mm
Feed
Belt, 250 rounds
Rate of
fire
450-600 rounds
per minute
400-500 rounds
per minute
400-500 rounds
per minute
The USA entered the
Great War in its late stages in 1917, with very small inventory of
mostly obsolete machine guns. Therefore, US soldirs in Europe had to
borrow machine guns from their French allies. A new heavy (medium by
modern standards) machine gun was required, and it was promptly
delivered by American gun genius John Browning. In 1917, after informat
but impressive test firing on Capitol heights, a heavy machine gun
(actually an improvement over Browning’s own design of 1901), was put
through more thorough tests by the US Army, which it passed with flying
colours. The first prototype to be submitted fired twenty thousand
rounds without any malfunction or part breakage – an astonishing
achievement even by modern standards. To strengthen its claims,
Browning submitted a second prototype which displayed similar excellent
results. Nearly 40,000 of those new M1917 heavy machine guns were
delivered by contractors to the US Army before the armistice, although,
not all of these reached the troops in France before the end of the war As
the war ended, the US army settled on the Browning M1917 as the primary
infantry machine gun. However, the cavalry requested a lighter weapon,
still capable of sustained fire, and this was provided in the form of
modified Browning machine gun, known as M1919. This weapon retained the
basic action of the M1917 water-cooled gun, but had a shorter,
air-cooled barrel, and used a light and compact tripod without traverse
& elevation mechanisms. Shortly after its adoption, the M1919A1
tank gun appeared, to be used on the US Mark VII tanks instead of the
obsolescent Marlin M1918 tank guns. The M1917 was upgraded to M1917A1
configuration in 1936 with the introduction of a strengthened bottom
plate in the receiver and a few other minor changes. In 1940 the US
army initiated trials for a new belt-fed light machine gun; several
designs were tried, mostly based on previous Browning designs, such as
the Springfield Armory gun, based on the A/N M2 aircraft MG with a
limited rate of fire, or the Rock Island Armory gun based on the M1919.
There were a few original weapons as well, such as Sedgley and Ruger
gas-operated machine guns. None of the guns was found suitable, so the
US Army adopted a slightly modified M1919A4 machine gun along with the
M2 tripod as an interim measure. This version of the Browning design
served as the primary medium machine gun for US troops through World
War 2 and Korea. When US Armed forces began the transition from .30-06
to 7.62 NATO ammunition in 1957, some of M1917 and M1919A4 machine guns
were converted to this ammunition, and few of those converted machine
guns were used by US Navy during early stages of Vietnam war.
Copies of
the Browning rifle-caliber machine guns were made under license in Belgium by FN
and in Sweden by Carl Gustaf factory. Before WW2 Poland also manufactured an
unlicensed version of the Browning water-cooled gun, the Wz.30.
All
Browning recoil-operated infantry machine guns are built using same
action, first introduced into service in 1917, and differ mostly in
details of the barrel cooling and associated arrangements, as well as
in mountings. The M1917 and M1919 machine guns are automatic
only, belt-fed machine guns, with water and air cooling respectively.
Both weapons fire from a closed bolt at all times, and both use the
same short-recoil action with a vertically-sliding locking block, which
rises up to lock the bolt to the barrel extension and drops down on
recoil to unlock the bolt from the barrel. An additional feature of the
Browning design is that it has a bolt accelerator, made in the form
of a lever located at the bottom of the receiver. Once the
barrel is unlocked from the bolt as the they recoil, the barrel on
being stopped strikes the accelerator, so the kinetic energy of the
recoiling barrel is quickly transmitted to speed the bolt's rearward
movement, improving the reliability of the weapon. The barrel is
screwed into the barrel extension and is not quick-detachable;
furthermore, once the barrel is installed in the weapon, the headspace
(the distance between the bolt face and the step in the chamber which
supports the shoulder of the cartridge case) must be adjusted prior to
firing, or the weapon may fail to fire or produce a serious jam. In
M1917 machine guns, the barrels are enclosed within a water jacket,
originally made from bronze and later from sheet steel. In M1919
weapons, the barrels are enclosed by tubular jackets with cooling
slots. The back of the receiver houses a bolt buffer, which consists of
several fibre disks which are used to soften the impact of the bolt on
the receiver rear plate. The cocking handle is attached to the bolt and
reciprocates with it in a slot made in the right receiver wall. Browning
rifle-calibre machine guns use a non-disintegrating ammunition belt of
cloth or steel, with a left-side feed. Alternate-side feed versions of
the M1919 were developed for tank use. The belt feed is of the two
stage type – every cartridge is first withdrawn from the belt towards
the rear by the pivoting extractor lever attached to the bolt. Once the
cartridge is clear of the belt, it is lowered into a T-slot cut in the
bolt face, and pushed forward into the chamber. Spent cartridge cases
are forced down the T-slot and out of the weapon through the opening at
the bottom of the receiver by the succeeding cartridges, or by the
pivoting belt extractor lever for the last cartridge case. The belt
feed is operated by the recoiling bolt via a swinging arm located in
the hinged receiver cover. The swinging arm is oscillated by a cam
track cut into the top surface of the bolt. As the bolt recoils, the
arm shifts the feed slide to the left, so its feeding claw engages the
next round. On the forward movement of the bolt, the feed slide moves
to the right, shifting the belt by one round. Since the gun
fires from a closed bolt it has a separate firing pin, powered by its
own spring, and housed inside the bolt along with the sear and cocking
lever. Upon the recoil stroke of the bolt, the cocking lever pulls the
firing pin back until it is engaged by the sear. Once the bolt is fully
in battery, a pull on the trigger raises the trigger bar so that it
acts on the sear and releases the firing pin. The standard firing
controls consist of a single rifle-type trigger at the rear of the
receiver and a pistol grip attached to the cylindrical buffer housing
which projects from the rear end of the receiver. Alternatively, dual
spade grips can be installed instead of the pistol grip, with a
push-type thumb trigger located between the grips. Standard
sights consist of a folding blade front and a frame-type rear. The rear
sight was invariably mounted on the receiver, while the front sight was
located on the water jacket on M1917 machine guns and at the front of
the receiver on M1919 machine guns. The standard mounting for
the M1917 machine gun was an M1917 tripod, a heavy all-steel
construction with integral traverse and elevation (T&E)
mechanisms. M1919A4 machine guns were usually issued with lighter and
more compact M2 tripod, which also had a T&E mechanism.
However, on M2 tripods the T&E mechanism could be discarded in
emergency situations, if it was damaged or not required for the present
mission.
The “light” M1919A6 machine gun
was fitted with a detachable shoulder stock which was clamped onto a
buffer tube, and a detachable bipod with adjustable legs which was
clamped to the barrel jacket. Additionally, a carrying handle can be
attached to the barrel jacket near the receiver. The M1919A6 barrels
were of lighter profile, and thus badly suited for sustained fire.
The
standard crew for an M1917 was four men; gunner, his assistant, and two
more soldiers to carry ammunition and water. A typical crew for the
M1919 machine gun is two men, a gunner and his assistant.