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37x94R 37mm Hotchkiss Revolver- and Rapid-Loading Gun | |||||||||||||||||||||||||||||||||||
With the appearance of the first torpedoboats in the
late 1870s the Navies
of the world realized the need for a quick fireing gun against those
torpedo
boats. The Hotchkiss cannons were developed and produced in France by
Benjamin
B. Hotchkiss and were later also licence built by Armstrong in England.
The
37mm Hotchkiss cannons spread all over the world, their use was
documented
at least in 28 different countries. In 1880 the French 37mm Hotchkiss revolver cannon was introduced to service in Russia. Later, the 37mm Hotchkiss rapid-loading cannon joined service. In 1918 about 4000 37mm cannons were listed in the Russian army. Sadly, no precise technical data is known about the
Russian ammunition in this caliber, the projectiles all have a weight
arround 500g and a muzzle velocity of about 400m/s (estimated). Ammunition used in the Hotchkiss revolver gun and Hotchkiss rapid-loading gun: |
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Partial cutaway drawings of the rounds listed above. Drawings from ECRA special bulletin 1990, cortesy of the German "Wehrtechnikmuseum" in Roethenbach/Pegnitz. | |||||||||||||||||||||||||||||||||||
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Picture of the first round with brass base fuze.
l=93,6mm, m=417g (without charge and without base fuze) ol=166,8mm,
headstamp: 0,311 1 | I.Z. anchor | G T | 2 1916 Imprinted in the projectile base: G S 17 14 (5) |
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37x155 37mm N-37 aircraft cannon | |||||||||||||||||||||||||||||||||||
The short recoil operated N-37 aircraft cannon was
based on the wartime NS-37 but considerably reduced in powder and
weight. It was introduced in 1946 to
replace the older NS-37 because the task of destroying mainly tanks and
ground
targets was obsolete and propper air to air combat probabilities with
higher
rate of fire were needed. The rate of fire of the N-37 is 400-450rpm, ammunition is fed in linked steel belts. The gun weights 103kg without ammunition load and was 2460mm long, barrel length was 1310mm. The MiG-15 and -17 carried one gun each with 40 rounds of ammunition load, the N-37 may still be in use today in underwing gun-pods. Cartridge cases are brass and filled with 127g of 4/1
FL propellant, they use the same percussion primer as the 45mm antitank
rounds use. Maximum armor penetration of the AP shell was 50mm. Ammunition used in the N-37: |
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Left picture:
37x155 Czech OZSV (HE-T) shell, m=735g, l=175mm,
ol=288mm, Vo=670m/s, 127g of 7/1 FL smokeless powder, high explosive:
25g TNT, Markings on fuze: A-37 18-56 fut 23-56 evr, Markings on shell:
27-fut-12-57-O 37x155 Czech AP-T shell, m=735g, l=165mm, ol=285mm,
Vo=670m/s,
127g of F4/1 smokeless powder, tracer is not fitted. Markings on shell:
22-fut-53 . < 13 |
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Right picture: 3 different Russian, one Czech and one East-German inert drill round. | |||||||||||||||||||||||||||||||||||
37x198 37mm NS-37 aircraft cannon | |||||||||||||||||||||||||||||||||||
This cartridge was developed for the Shpitalny Sh-37
cannon, but this cannon was very unreliable and only a small test batch
was fitted to LaGG-3 and Il-2 fighters for trials. The experimental Sh-37 was replaced by the more reliable NS-37 in 1942, the gun was mainly developed by A. Nudelman and A. Suranov at the "Precision Engineer Design Bureau" called "OKB-16" later on. As ammunition for the Sh-37 with cartridge case dimension 37x198 was readily developed and in production that time, the NS-37 adopted this caliber. The NS-37 was called 11-P-37 in prototype state, it had a rate of fire of 250-260rpm and weighted 150kg. The recoil operated cannon was intended to engage German tanks and armored vehicles, as well as to destroy hostile aircraft with a single hit. The AP shells were belt fed and could penetrate 40mm up to an angle of 45°; the NS-37 cannon was 3410mm long and had a barrel length of 2300mm. It was fixed to the LaGG-3 in the engine vee and on the Il-2 in underwing pods, and on the Su-8 in underbelly mounts. But most NS-37 cannons were mounted between the cylinder banks of the engine of the Yak-9T fighter, ammunition load was 32 rounds. It was used in air to air and air to ground combat successfully, about 8000 cannons were built. Rate of fire was quite low for air combat and recoil was so violent that pilots were trained to fire only three-round bursts. So no wonder that this gun was soon replaced by the N-37 with less powerful ammunition as described above. Ammunition used in the NS-37: |
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Probably, target practice and drill rounds were used.
A special tungsten carbide core AP projectile has been developed, however none has been discovered so far, so it may not have been itroduced to service. |
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37x252SR 37mm Russian M1939 AAA | |||||||||||||||||||||||||||||||||||
This caliber was developed from the Swedish 25mm
Bofors AA gun
sold to
Russia in the 1930s. The design was a joint task by L. A. Loktev and M.
N.
Loginov in the Design Bureau of Artillery Plant No. 8 at Kaliningrad.
The
M1939 had certain similarities with the later 40mm Bofors L/60 AA gun
like clip feeding and a similar carriage. The M1939 was
introduced
in
Autumn 1939 and is a AA cannon of 2,1 tons weight (without optional
shield)
and fitted with a barrel 2740mm long. Rate of fire was 160 to 180rpm,
its
ammunition was fed in 5-round charger clips. Maximum range was 9500m
horizontally
and effective vertical range 3000m, the AA gun was operated by 8 men
and
had a fire unit of ammunition of 200 rounds. The M1939 was recoil
operated
and air cooled, it was also modified after the war to water cooled
cannons
designated 70-K as single barrel and V-11M as double barrel cannon. Two
Naval
versions were also used in WWII, a single and a twin barrel mounting
designated
3,7cm/67 M1939. The towed M1939 AA gun was still widely used after the war, as well in the Soviet Union, its associated states, Yugoslavia and China and it is still in service. The twin barrel gun was also made for export and is still in service in Algeria and Egypt. China built its own versions as single barrel Type 55, as twin barrel Type 65 and 74 and as advanced twin barrel P793 anti aircraft gun with modernized fire control system. Cartridge cases are brass with a KV-2U percussion
primer screw,
the powder charge is held in place by a cardboard assembly. The
propellant consists of 7/14 nitrocellulose powder with a by-charge of
black powder, the
inner walls of the case are coated with waxed paper, that acts as
phlegmatiser. A piece of lead-tin wire is located inside the case to
act as decoppering agent, because driving bands are copper. The ammunition used post WWII: |
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Inert drill rounds are used as well. | |||||||||||||||||||||||||||||||||||
The above picture was kindly provided by Harry Galloway, it shows different live and inert drill rounds. | |||||||||||||||||||||||||||||||||||
40mm GP-25 Kostyor grenade launcher | |||||||||||||||||||||||||||||||||||
This caliber is no fixed cartridge, but it has a
propelling section with
percussion primer to the rear. Actually, two types of ammunition are
used
in te GP-25 launcher, that may be attached underbarrel to the AKM and
AK-74
assault rifles. The launcher is similar to the US M203 launcher, but
the
GP-25 is a rifeled muzzle loader, it is 280mm long, weights 1,2kg and
maximum
range is 400m. The grenade launcher is locked in position under the
assault
rifle barrel behind the trigger guard and attached to the muzzle
adaptor
at the front. The GP-25 is now replaced by the improved GP-30 Obuvka
launcher. The GP-30 weights 1,5kg, fires with a double action trigger and has a sighting range of 400m. Also developed is a six barrel grenade rifle 6GP-30 that has a extendable stock and a revolving breech that is preliminary wound by a spring to achieve a firing rate of 15-18 rds/min. The grenade rifle is 510mm long, 680mm with extended stock and weights 6kg. The grenade launchers fire VOG-25 and VOG-25P standard
fragmentation rounds. The latter model is provided with an expelling
charge which ensures the rebound of the grenade on impact and its
airburst to effectively defeat a screened target. In addition, a
special purpose Gvozd gas grenade can also
be used to enhance the weapon versatility. The first type of shell is
the
VOG-25, a steel shell with outer obturations that look like a driving
band,
but these are actually the fragmentation grooves. This body is filled
with
48g of high explosive and closed with an impact nose fuze, a light
alloy
cap covers the fuze except from the tip. The impact fuze remains
sensitive
even on snow, bog and water surface. A short cylinder protrudes out of
the
base, this is the propelling section, filled with P-200 propellant. A
central
percussion cap is surrounded by ten small nozzle holes that provide a
high/low
pressure boost. This grenade uses the VMG-M or VMG-K nose fuze. Ammunition is manufactured by Russia. |
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Drill rounds exist as well, of course. |
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Four drill grenades and one VOG-25P, the cap has been removed on the third grenade from the right. | |||||||||||||||||||||||||||||||||||
40.6mm Djakonoff rifle grenade | |||||||||||||||||||||||||||||||||||
This WWII caliber consists of only one type of shell
that is projected by the Djakonoff 30 rifle grenade assembly that could
be fixed to the muzzle of all standard 7.62mm rifles. The shell, type
"VGD" consists of a steel envelope
that may have fragmentation grooves or not. The envelope is closed on
the
top with an ogive cap and to the rear with the driving band and fuze
assembly.
A central tube leads through the entire shell, to allow the use of
standard
ball ammunition for projecting. Three studs on the driving band located
on
the lower third of the shell transmit the spin of the grenade
projector.
Below the driving band is a ring with imprinted numbers for adjustment
of
the delay time of the powder burning fuze. The base of the shell is recessed to act as seal against the powder gases, this recess also takes an optional additional powder charge for greater range. The detonator cap reaches deep inside the shell, between the outer wall and the central tube. |
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Technical data:
The shell is 115mm long and weights 350g, it has a HE
filling
of 50g of TNT. If other types of HE are used, the gray cap is painted
in
other colors. The muzzle velocity is 54m/s with a standard 7,62 Mosin
Nagant ball rifle cartridge, with an additional powder charge of 2,5g
of smokeless powder in a silk bag, the muzzle velocity was 110m/s. The
according maximum ranges were 300m and 900m. The powder delay time fuze
could be adjusted between
3 and 12 sec., the fuze is ignited by the hot powder gases. The shell
produces
about 340 fragments on detonation, that form a deadly radius of about
50m. |
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Legend: m= mass of projectile, om= mass of complete round, pm=mass of propellant, l= length of projectile, ol= overall length of complete round, Vo= muzzle velocity, cartridge case headstamps are given in the clockwise system, the clock-sections divided by "|" for better reading. The "|" does not mean an imprinted line in the headstamp. Example: symbol at 12 o´clock | 3 o´clock | 6 o´clock | 9 o´clock | |||||||||||||||||||||||||||||||||||
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