The 37mm M3 Gun

In the development stage, the US War Department, like most national militaries, first looked at foreign guns that met the weapon standards and purchased them or co-opted the desired elements into the existing system to make for a pseudo-indigenous end-product.

The 37mm Gun M3 became America's first anti-tank gun system to enter service.
Even before World War 2, the United States Army had already begun development of an anti-tank gun. The system was required to weigh less than 1,000 lbs, able to be towed by the standard jeep and field a projectile that could pierce tank armor of the then-current tank systems of the 1930's.

Two of the field guns being evaluated were the French Hotchkiss 25mm and the German Rheinmetall 37mm gun. In the 1930's, the German gun had the capability of destroying any tank in service anywhere in the world.

In January of 1937, the US Army Ordnance Department assigned the infantry branch to oversee design work. They sought a lightweight gun which could be moved about the battlefield by a crew of 4 to 6 personnel. This desire for mobility restricted use of larger-caliber guns greater than the 37mm.

The Army felt confident with the caliber, as did other armies around the globe during the 1930s (to include such types as the Swedish Bofors, Japanese type 94 and Type 1 and both Czechoslovakian vz. 34, vz. 37 guns). As such, the US military opted to go with the German 37mm design as their template, resulting in the American "M3" - a design, despite her origins in the German product, was significantly revised for American use and even used different ammunition.

The gun was manufactured by Watervliet Arsenal, New York that was founded in 1813 (and still in service today, though referred to as 'America's Cannon Factory'). The barrel was small enough to be forged as a single unit. The decision of the all important rifling became 12 right-hand twisted grooves and a single turn in 25 calibers.

The breech mechanism selected was of the vertical sliding block type. The square breech ring maintained the breech end of the barrel screwed into it. The breech ring was a solid piece with the center removed to allow the block to slide vertically up and down inside it. The vertical type was liked by the crews because the top face of the block could act as a loading tray for the shell, and the block could not jam the trail if the breech was opened at a high elevation. The breech ring and block were designed to withstand the violent rearward caused by the propellant gas pressure when the gun fired. The mechanism was made up of seven main parts: the breech ring, breech block, gearing (to open and close the breech), breech block buffer, extractors (to remove the empty cartridge), devices to limit movement and safety devices to prevent firing until the block and/or gearing was fully closed.

The carriage was built by the Rock Island Arsenal in Illinois. The arsenal started producing ordnance and other military items in the 1880's and is now the largest government-owned weapons manufacturing arsenal in the United States. The carriage was of a split-trail type with pneumatic air-filled tires allowing for better towing by a jeep.

When the gun was detached from the towing vehicle, the crew would move the gun into position for firing by hand. For stability, the wheel segment supports mounted on the axle next to the wheels could be lowered to provide a more stable firing position. They could then be raised before the gun was moved to the next firing position.

The telescopic sight and both elevation and traverse controls of 60 degrees were located along the left side of the system so the gunner could aim the weapon. The maximum elevation was +15 degrees and the maximum depression could be -15 degrees. The traverse gear had a release mechanism which allowed free movement of the barrel in case a quick traverse was needed with the normal 5-man crew.

Other than practice and dummy rounds, the primary ammunition used with the M3 were made up of three types - the M51 APC, M63 HE and M2 canister projectiles. The M51 anti-tank armor piercing capped shot shell (APC) which weighted 3.48 lbs (1.579 kg) and had steel shot with a 3-second tracer and could penetrate 2.4 inches of armor at 500 yards with a maximum range of 7,500 yards. The M63 was a "general purpose" high explosive (HE) shell weighing 3.13 lbs (1.420 kg) and having a maximum range of 12,800 yards. The explosive round was encased within a steel covering and fitted 0.85 of a pound of TNT with a BD fuse. The M2 canister anti-personnel round weighed 3.49 lbs (1.583 kg) and contained 122 lead balls.

The US Army organized the M3 within infantry anti-tank battalions. Four 37mm guns were assigned to be towed by 10-ton trucks or jeeps and twelve such guns had 10-ton trucks as their prime movers. A division fielded twenty-four guns with many of these towed by M2 halftracks. By 1942, the Army had formed its first airborne divisions and forty-four M3's were assigned to field parachute artillery. The new 10th Mountain Division had twenty-five of the 37mm guns assigned to its infantry regiments. During 1942, all Army armored divisions had a total of sixty-eight M3's in service. At the beginning of the war, the Marine Corps was committed to using the 20mm gun for the anti tank role but were furnished the newer, more effective 37mm gun within time. By 1943, the 37mm gun had become the AT weapon of choice of the Marines. 

In the Battle of Kasserine Pass of 1943 in North Africa, advanced medium and heavy tanks systems fielded by the Germans had already made the 37mm gun a marginal anti-tank weapon. The M3 did prove useful against lighter Italian armored components, however, and was effective against the smaller Renault R35 tanks throughout the Italian Campaign. Similarly, in the Pacific Theater, the Japanese Army was keen on using light tanks and the M3 proved adequate in stopping them. On Guadalcanal, US Marines and, later, the Army, used the M3 with good results against the Type 95, Type 96, and Type 97 tanks with their 12mm armor. The Japanese "bonsai" attacks - essentially suicidal front offenses - were perfect for the canister shot of the M3 and, with the system being very mobile, the gun could relatively easily be directed to fire all over the island and against mountain terrain - no Japanese Army cave or pill box was safe. At the Battle of Tarawa, Marines are known to have picked up a M3 over a five foot seawall to fire directly at Japanese bunkers.

If the M3 proved to have a limitation, it was in her rather smallish shield meant to protect the crew against incoming enemy fire. As a result, American Marines would take it upon themselves to weld additional shielding onto the M3 structure. Though this increased her operational weight, it provided priceless protection for her all-important crew. 

The M3's wartime use was exceptional and her reach made sure she would be remembered in World War 2 history. Her combat forays made for great marketing and she was introduced within the inventories of foreign nations within time including many American-allied nations in South America. Despite being phased out of service with the American Army soon after the end of World War 2, the M3 survived in a frontline role with other armies into 1970. Notable operators included the Soviet Union (via Lend-Lease), the United Kingdom, Canada and France. South American operators settling on the M3 included Bolivia, Chile, Columbia and El Salvador. Cuba also armed with the M3, as did China.

T3 was used as the prototype designation. T7 was another prototype but this fitted with a semi-automatic sliding breech. The T8 was yet another prototype but differed in fitting a Nordenfelt sliding breach. The T9 prototype was a 37mm automatic cannon that became the M4 production model. The M10 prototype became the M3 production model and sported the manual vertical block breach. The M3 designation signified the base production series family line. The M3A1 was noted for the introduction of a threaded barrel to accept an optional muzzle brake - this being introduced in 1942. The M5 was a tank-mounted version of the M3 gun with a shorter barrel and introduced in 1939. The M6 was another tank-mounted version with the original barrel length, a semi-automatic breech and introduction beginning in 1940.

Dimensions:
Overall Length: 12.86ft (3.92m)
Width: 5.28ft (1.61m)
Height: 3.15ft (0.96m)

Weight: 0.5 US Short Tons (413kg; 911lbs)

Kalashnikov AK-9 compact

The AK-9 is the most recent addition to the line of the Russian-made weapons, built for the family of the sub-sonic 9x39 ammunition, which includes SP-5 ball and SP-6 armor-piercing rounds. The AK-9, developed by the Izhevsk Machine building plant (IzhMash, the home of Kalashnikov assault rifles) is intended to compete with already established weapons such as AS silenced assault rifle and 9A-91 and SR-3M multipurpose compact assault rifles. The AK-9 is intended for use by special elements of the Russian army (recon troops) and by various Law Enforcement agencies, engaged in anti-terror, anti-drug and anti-organized crime operations.

The AK-9 is based on the so-called "hundred series" of Kalashnikov assault rifles, such as AK-104, but with certain improvements. It features same tried and proven gas operated, rotary bolt action and same "Kalashnikov-style" controls including reciprocating bolt handle, safety/fire selector lever and overall layout with side-folding polymer buttstock. Polymer furniture is improved with addition of the accessory Picatinny rails on the bottom of the forehand, and the left side of receiver is fitted with Russian-standard scope rail. Barrel can be fitted with specially designed quick-detach silencer (sound moderator), which is especially effective with 9x39 subsonic ammunition. Magazine is made of black polymer, holds 20 rounds of ammunition and appears to be of proprietary design, not compatible with other (competing) weapons of the same caliber, which are already in service with Russian military and law enforcement.

Caliber: 9x39 mm SP-5, SP-6
Action: Gas operated, rotating bolt
Overall length: 465 / 705 mm; 646 / 881 mm with silencer
Weight: 3,1 kg with empty magazine, 3.8 kg with silencer installed
Magazine capacity: 20 rounds

Aeromarine 39 Trainer

The Aeromarine 39 was a two-seat plane for land-based or seaplane training ordered by the US Navy in 1917. The versatile aircraft was built by the Aeromarine Plane and Motor Company of Keyport, New Jersey. The design was a standard biplane configuration and construction. The aircraft was fabricated so the pontoons could be hastily detached and replaced with the supplied wheeled undercarriage for land or carrier operations. As time went on, fifty of the originally built designs were reassigned under the designation of 39A. The 39A models featured twin floats and the plane was powered by a Hall-Scott A-7 engine. The Hall-Scott A-7 was an early aircraft engine with a straight 4 configuration and could produce a maximum of 100 horsepower (75 kW). These engines suffered from consistency problems and many were prone to catch fire while in operation forcing the manufacturer to start using the Curtiss OXX powerplant. Other redesigns increased the wingspan for more lift needed for those water take-offs. This became known as the 39B. Additional changes included a single pontoon with outrigger floats, plus an enlarged vertical tail surface.

The Aeromarine 39 became the first American aircraft to land on a moving carrier in 1922.

On October 26, 1922 Lt.Cdr. G. deC.Chevalier, piloting an Aeromarine 39, circled the USS Langley as the ship was underway at 10 knots. Chevalier successfully landed his plane on the moving deck of the Langley. The first such landing on an American carrier.

Specifications for the Aeromarine 39A

Length: 30.35ft (9.25m)
Width: 46.98ft (14.32m)
Height: 14.76ft (4.50m)
Maximum Speed: 73mph (117kmh; 63kts)
Maximum Range: 273miles (439km)
Rate-of-Climb: 0ft/min (0m/min)
Service Ceiling: 8,202ft (2,500m; 1.6miles)

Empty Weight:1,940lbs (880kg)
Maximum Take-Off Weight:2,504lbs (1,136kg)
Engine(s): 1 x Hall Scott A-7 piston engine generating 100 horsepower.

Heavy Tank M103

The M103 was a mammoth tank design delivering armor protection and firepower at the expense of sheer size and speed. Stemming from the T43 trial version, the system evolved into the T43E1 which became the standardized M103. Main armament consisted of the heavy caliber rifled 120mm main gun mounted alongside a conventional 7.62mm coaxial mount in the turret. The commander was afforded a heavy caliber 12.7mm machine gun at his cupola, but this was externally mounted and classified as an air defense weapon. Ammunition supply for all guns was ample and five crew were required for optimal operation. Along with the driver and commander, there was the standard gunner along with two loaders.

With the Cold War in full bloom, design of heavy tanks for the United States Army increased in an effort to mimic the success of the World War Two / Korean War-era M26 Pershing Heavy Tank.

 
Despite the formidable array of arms, the system was dogged by reliability problems, a short road range and its sheer size. In the temperate and hilly terrain of Europe, the M103 faired below expectations. It's size alone made the system very difficult to conceal along the Cold War fronts throughout Europe. A new engine, bringing the road range from the measly 80 miles to over 300 miles was implemented in what would become the M103A2 but it was not meant to be. The M103 was dissolved from service with the United States Army in a few short years, bringing an end to the new generation of M103 Heavy Tank.

Avtomat

Captain V. Fedorov of the Russian Imperial Army (later - a general of Soviet Army) started development of the self-loading rifle in 1906. His first rifle was chambered for standard Russian 7,62x54R ammunition, held 5 rounds in fixed magazine and fired only semi-automatically. In this job Fedorov was supported by his apprentice V.Degtyarov (who latter became one of most important Soviet small arms designers of pre-WW2 generation). Fedorov rifle entered trials in 1911. In 1912 the Rifle Commission of Russian Army decided to order 150 more Fedorov rifles for further trials, and in 1913 Fedorov submitted a prototype automatic rifle, chambered for his own experimental rimless cartridge of 6,5mm caliber. This new ammunition was more compact that Russian 7,62x54R, better suited for automatic weapons (because of rimless cartridge) and has less recoil. This experimental cartridge fired pointed jacketed bullet weighting 8,5 gram at initial velocity of 860 m/s(muzzle energy 3140 Joules as opposed to 3600 - 4000 Joules muzzle energy of 7,62x54R ammunition). 6,5mm Fedorov rifles were tested late in 1913 with good results; these rifles still had fixed magazines loaded from stripper clips.Further trials and development were stopped by the start of World War One. In 1915, however, the need for lightweight automatic arms forced Russian Army to order manufacture of Fedorov automatic rifles with detachable magazines of bigger capacity. Since production of the new cartridge was out of question, it was decided to convert 6,5mm Fedorov rifles to Japanese 6,5x50SR Arisaka ammunition which was in abundance, being purchased through Great Britain along with Arisaka rifles. The change of ammunition involved only minimal changes to the rifle, including chamber insert and new range scale for rear sights. In 1916 Weapons Committee of Russian Army decided that it is necessary to order at least 25 000 of Fedorov automatic rifles. In early 1918 orders for Fedorov rifle were limited to 9000 guns, but as result of turmoil of the revolution and following Civil war only 3 200 Fedorov rifles were manufactured in the city of Kovrov between 1920 and 1924, when production was finally stopped.

Fedorov "Avtomat" - the first practical assault rifle ever adopted

It is interesting that at the time of initial orders Russian Army considered Fedorov automatic rifles as substitute light machine guns; although in actual use Fedorov rifles were used as individual armament for infantry soldiers,exactly in the tactical niche of modern assault rifles. Fedorov automatic rifles served with Russian and later with Red (soviet) Army through WW1, Civil war and until late twenties, when it was decided to retire all rifles and machine guns that used non-standard (other than 7,62x54R) ammunition, and Fedorov rifles were put into reserve storage. The last conflict that saw action of Fedorov rifles was Winter war with Finland in 1940, when some Fedorov rifles were withdrawn from storage and issued to elite units of Red Army.

One important note must be made about the name of Fedorov rifle, which is universally known as "Avtomat" (automatic). This name was apparently devised by Russian small arms expert Blagonravov during mid- or late twenties. At the time, this term was used to designate any shoulder-fired automatic weapon, be that rifle or submachine gun. Up until now "avtomat" is unofficial Russian term for automatic weapon. Today this term is most often used for weapons, generally known as "assault rifles", and therefore Fedorov's "Avtomat" can be considered as one of the world's first practical assault rifles. At the time of its peak usage (1918-1924) there was only one practical automatic rifle made in the world which fell into same tactical class - the Browning's BAR M1918. Initially Bar was intended to be used as assault rifle, with individual soldiers firing itfrom the shoulder or hip during assaults on enemy trenches; however, Browning's rifle was almost twice as powerful (comparing muzzle energy of US .30-06ammunition used in BAR and 6,5x50SR used in Avtomat) and exactly twice as heavy compared to Fedorov's rifle. Therefore BAR soon evolved into light machine gun,while Avtomat set the pattern for the whole new class of infantry weapons, which rose to its heights during late stages of WW2 and especially afterwards.

Fedorov "Avtomat" action, removed from the wooden stock. Note that barrel is in full recoil position and locking plates are lowered and bolt isunlocked (right locking plate is visible in front of the round cocking handleknob).

Finally, we shall note that Fedorov's Avtomat was not without flaws. Its recoil-operated action was sensitive to fouling; early production guns suffered from non-interchangeability of parts, including magazines; disassembly and especially re-assembly was somewhat complicated. Despite these flaws, it was a formidable and historically important weapon, and, ironically, its ballistic properties are very close to modern idea of "ideal" assault rifle and its ammunition.

Diagram showing the locking action of Fedorov avtomat. Top - bolt is locked tothe barrel, bottom - barrel is in full recoil, bolt unlocked and partiallyopened
Parts are numbered as follows: 1 - barrel; 2 - bolt; 3 - locking lug (one of two);4 - fixed lug in receiver.

Fedorov's "Avtomat" is short recoil operated, locked breech weapon which fires from closed bolt. The bolt locking is achieved by two locking plates, located at either side of the breech. Those plates are allowed to tilt slightly down and up, locking and unlocking the bolt with special lugs.The barrel is fluted to save the weight and improve cooling. Trigger unit uses a pivoting hammer to fire, and separate manual safety and fire selector levers are installed within the trigger guard. The stock is made from wood, with semi-pistol grip and additional vertical fore grip in the front of the magazine.The curved box magazine held 25 rounds in two rows, and was detachable. A special bayonet was attached to the front of the steel heat-shield below the barrel. Standard open sights with tangent rear were installed on the barrel.

Caliber: 6,5x50SR Arisaka
Action: short recoil operated
Overall length: 1045 mm
Barrel length: 520 mm
Weight: 4,4 kg empty
Rate of fire: 600 rounds per minute
Magazine capacity: 25 rounds

Antonov An-2 multi-role light utility biplane

The Antonov An-2 is a multi-role light utility biplane initially produced under the Soviet flag. Despite its 1940's pedigree, the system has continued service and operations throughout the world and production itself has totaled over 18,000 examples as of this writing. The An-2 goes under the NATO codename of "Colt" and is designated in US DoD nomenclature as the "Type 22". The Soviet Union/Russia, Poland and China have all lent a hand in production of local base and specialized variants. Operators are numerous and range from those with military service to those with civilian-minded needs.

The Antonov An-2 Colt biplane was developed to replace the Polikarpov Po-2 in the utility and agricultural roles.

The engine - powering a four-bladed propeller - is held in the extreme forward of the fuselage to which the cockpit is situated directly aft. The cockpit is heavily glazed and observation port windows can be seen along the fuselage sides. The wing arrangement on this aircraft is of a sesquiplane (uneven span) biplane assembly with the top wing noticeably wider than the lower element. Each wing is connected via a single large vertical strut making up a single wing bay and each wing system showcases dihedral (upward angle). The fuselage tapers slightly into the empennage to which is affixed a single large, smooth-edge vertical tail fin and its applicable stabilizers mounted to either tail fin side. Like other aircraft of this classification, the An-2 sports a pair of fixed landing gear legs complimented by a smaller tail wheel. The main landing gear legs feature wheel bogies decidedly angled inwards with each leg braced at two points along the underside of the fuselage. Power is supplied from a single Shvetsov ASh-62IR 9-cylinder, supercharged radial piston engine of 1,000 horsepower. Maximum speed is a reported 160 miles per hour with a listed range of 525 miles and a service ceiling equal to 14,750 feet.

Externally, the An-2 shares many similarities with other light aircraft of this class.

Accommodations are generally made for a crew of one pilot but an observer/co-pilot is preferred. Cabin seating can hold an additional 12 passengers.

Beyond the typical prototype and evaluation models, the Soviet Union/Russia has produced the majority of the existing An-2 variants while Poland contributed as well.

Produced types ranged from basic observation and reconnaissance aircraft to specialized floatplanes, artillery observation, mail carrier, cargo transport, VTOL-minded projects, survey and photographic platforms, fire bombers and firefighters, research and VIP transports. Agricultural versions have seen extended use in for both Poland and China.

China has produced many versions of the An-2 beginning with the Fong Shou-2 ("Harvester-2").

This was the first An-2 built to agricultural specifications. The Nanchang Y-5 is a transport version since taken over in production by Harbin with 727 examples delivered. Nanchang Y-5II was an agricultural form seeing production number 229. Shijiazhuang Y-5A was a light passenger model based on the An-2T and produced in 114 examples. The agricultural derivative became the Shijiazhuang Y-5B based on the An-2 SKh. The PLAAF makes use of the Shijiazhuang Y-5B(T) para-drop model. The Nanchang Y-5C is an amphibious version of the Y-5A while the Nanchang Y-5D is a bomber crew trainer. The Nanchang Y-5K became a VIP passenger transport seating five.

Notable operators of the An-2 include (or have included) Afghanistan, China, Cuba, East Germany (and Germany proper), Egypt, Georgia, Hungary, Iraq, Laos, Lithuania, Macedonia, North Yemen, North Korea, Poland, South Korea, Romania, Russia, Serbia, Somalia, Sudan, Syria, Turkey, Ukraine, Vietnam, Yemen and Yugoslavia.

Despite its fragile appearance, the Antonov An-2 has seen its fair share of combat action.

It was debuted in such a manner during the Korean War (1950-1953) and later in the Vietnam War - the latter by the North Vietnamese. Some An-2's were converted from their traditional crop dusting roles to become make-shift bombers in the Croatian War of Independence (1991).


Specifications for the Antonov An-2 (Colt)

Dimensions: Length: 40.68ft (12.40m) Width: 59.71ft (18.20m) Height: 13.45ft (4.10m) Performance: Max Speed: 160mph (258kmh; 139kts) Max Range: 525miles (845km) Rate-of-Climb: 700ft/min (213m/min) Service Ceiling: 14,764ft (4,500m; 2.8miles)	Structure: Accommodation: 2 + 12 Hardpoints: 0 Empty Weight: 7,275lbs (3,300kg) MTOW: 12,125lbs (5,500kg) Powerplant: Engine(s): 1 x Shvetsov ASh-62IR 9-cylinder supercharged radial piston engine delivering up to 1,000 horsepower.
Armament Suite: Usually none. Some may be fitted with defensive machine guns. Crews may carry individual weapons while other An-2s modified for dropping bombs as needed.

D 20

The M1955 was developed in the 1950s to late to be deployed in the Great Patriotic War 1939-1945. However this howitzer has shown reliability and power in numerous wars deployed by scores of nations. The Soviet Union design bureau awarded the contract to Petrov Artillery and the M1955 was built in Yekaterinburg a city in central Russia used in WW II to relocate many heavy factories and many stayed after the war.

The D-20 can be towed by a variety of tracked and wheeled vehicles.

The D 20 was placed on an existing carriage used by the D 74 and was a common practice used by the Soviets. The gun proved to be well designed and rugged enough during field trails. An 8 man crew was needed to man the howitzer an AT-S medium tractor was used for towing along with the URAL-375 6x6 heavy truck. The Russian government still uses the M1955/D20 and still field about 1,000 guns in their arsenal. An initiative development was a semiautomatic vertical sliding wedge breech block.

The major copy was from The Peoples Republic of China that produced the Type 66. This variant has been shipped all around the globe. Type 66 was made with few changes making most Soviet parts interchangeable along with using all types of 152 mm ammunition. The barrel was 5.195 m (17ft 0.5 in) long using a double baffle muzzle to reduce the recoil. A shield was mounted to protect the breach and recoil mechanism. The crew also was protected to some degree. A firing pedestal was lowered to the grown before firing and the split tail carriage was also rested on the pedestal, this allowed a full 360 degrees traverse.

The main projectile used by the howitzer was the HE-FRAG that weighted 95.92 lbs which led to the sustained rate of fire to 1 rpm. Special types included an AP shell 107.54 kg that would penetrate 124 mm (4.88 in) of armor at 1,000 m (1,095 yards). Smoke and illuminating projectiles are available along with a shell contained flechettes for use against infantry and another that spread anti personnel mines in flight.

A rate of 5 to 6 rounds-per-minute can be achieved with 1 round-per-minute in the sustained firing role. Range for an HE-FRAG projectile is reported at 19,040 yards while a rocket-assisted projectile can land within 26,245 yards. Elevation of the barrel is -5 degrees to +65 degrees with a traverse of 58 degrees.

Specifications for the D-20 (M1955)


Overall Length: 26.57ft (8.10m)
Width: 7.71ft (2.35m)
Height: 8.27ft (2.52m)
Weight: 6.3 US Short Tons (5,700kg; 12,566lbs)

Armament Suite: 1 x 152mm Main Gun

Ammunition: Varies. Typical 152mm ammunition type is Frag-HE, OF32.