Sabtu, 05 April 2014

Beretta ARX-160 assault rifle (Italy)

Beretta ARX-160 assault rifle, early prototype (ca.2008)

Beretta ARX-160 assault rifle, production version (2013) in 5.56x45 NATO

Beretta ARX-160 assault rifle, production version (2013) in 7.62x39 M43 Russian 
Beretta ARX-160 assault rifle, production version with GLX-160 grenade launcher
Beretta ARX-100 self-loading rifle for civilian use, in 7.62x39 Russian

Beretta ARX-160 assault rifle partially disassembled

Caliber: 5.56x45mm NATO, 7.62x39 M43
Action: Gas operated, rotating bolt
Overall length: 820-900 mm with 406 mm barrel and butt in ready position; 680 mm with butt folded
Barrel length: 305 mm / 12" or 406 mm / 16", quick changeable
Weight: ~ 3.1 kg with 406 mm barrel, w/o mag
Rate of fire: 700 rounds per minute
Magazine capacity: 30 rounds

The Beretta ARX-160 assault rifle is manufactured by famous Beretta company in Italy. Starting 2012, ARX-160 rifle is in use by Italian army. It is also offered for export, with initial customers being Special Forces of Algeria, Egypt and Kazakhstan (latter bought 7.62x39 version). A semi-automatic only version of the ARX-160 is offered for civilian sales as Beretta ARX-100 rifle, also in 5.56 / .223 Rem and 7.62x39.

The Beretta ARX-160 assault rifle is gas operated weapon that utilizes conventional piston-operated action, with short stroke gas piston located above the barrel. Barrel locking is achieved by more or less conventional rotary bolt. Unlike most other assault rifles, the Beretta ARX-160 assault rifle features quick-detachable barrels, which can be changed by operator in the field by depressing the barrel release button (located on right side of receiver, in front of magazine housing), pulling the barrel forward and out of the gun, and then inserting another (or same) barrel back. The receiver consists of two parts, upper (which holds barrel and bolt group) and lower (which hosts magazine housing, trigger unit and pistol grip). Both halves are made from impact-resistant polymer and connected using special quick-release locks, so there are no pins to push out (and lose). Another interesting and unusual feature of the Beretta ARX-160 assault rifle is that it has selectable left / right side ejection system with dual ejection ports (on either side of the gun) and user-switchable left / right position of cocking handle. To change the direction of empty case ejection, user has to push the cross-bolt button, located above and slightly to the rear of pistol grip, by the tip of the bullet (or other pointed item). This affects dual extractor-ejector claws, installed on the bolt, forcing them to eject spent cartridge to the desired side without any further disassembly of the gun or parts change. Charging handle, which is attached to the bolt carrier, also can be installed on either side of the gun. The Beretta ARX-160 assault rifle fires from closed bolt, in single shots and full automatic mode, and has ambidextrous safety / fire mode selector switch conveniently located above pistol grip. Upper receiver is fitted with full-length Picatinny type rail, made of aluminum, which can accommodate a wide variety of sighting equipment, including iron, telescopic, red-dot or electronic sights. Standard open sights are mounted on folding bases using rail interface. Additional lengths of Picatinny rail are installed on the forend on 3-, 6- and 9- o'clock positions. Lower (6-o'clock) position rail is strong enough to host GLX 160 40mm single-shot grenade launcher. Standard buttstock is also made of plastic, and folds to the right side. The buttstock is of telescoped, user-adjustable design.

Senin, 11 Maret 2013

MG 42 and MG 3 machine gun (Germany)

MG3 machine gun in "light machine gun" role, as made under license in Pakistan.

 MG3 machine gun in "mdeium machine gun" role, as made in Iran.

Germansoldier aiming the MG3, fitted with EOTech holosight red-dot optics anda 50-round plastic belt container (which appears to be empty).

 MG 42 machine gun in LMG role, right sideview with bipod folded and carrying sling attached.

MG 42 machine gun in MMG role, on infantrytripod mount Lafette 42.

 MG 42 machine gun in LMG role, left sideview, with bipod extended.

Barrel change for MG 42 - barrelis unlatched and its breech part is exposed for removal.

 MG-42, bolt assembly schematic.

 MG-42,bolt assembly, with locking rollers and extractor claw seen at theright and belt-feed operating stud at the left.

  MG 42 MG 3
Caliber 7,92x57 7,62x51
Weigth 11,6 kg (gun) + 20,5 kg (Lafette 42 trpod) 10,5 (gun) + various tripods
Length 1219 mm 1225 mm
Lengthof barrel 533mm 565 mm
Feed belt belt
Rateof fire 1200- 1500 rounds per minute 700-800or 1100-1200 rounds per mniute

With adoption of the MG 34 machine gun the Wehrmacht had the weapon that was envisaged some 20 years before, and the MG 34 bears the distinction of being the first practical universal (or general purpose) machine gun. While the MG 34 was good and practical, it was certainly not ideal. German experts wanted their machine guns to fire faster, while being simpler and less costly. A high rate of fire was desirable both for AA applications and for surprise flanking fire against targets moving through the battlefield. As early as 1937 HWaA issued a request for the next new universal machine gun,and three companies received development contracts – Johannes Grossfuss AG, Stubgen AG and Rheinmetall-Borsig AG. In 1939 a commission selected the Grossfuss-made MG 39 prototype for further development. Designed by engineer Gruner (often wrongfully referred to as Grunow) and small arms designer Horn, new weapon, in accordance with HWaA request, had a stamped steel construction, combined with locked breech, short recoil action. Initial trials suggested that the Grossfuss MG needed further development, and in late 1941 a small batch(about 1500 pieces) of improved guns was manufactured for troop trials as the MG 39/41.
 The new machine gun, while being made tolower standards of fit and finish, proved to be quite functional and reliable (a feature that the much more “refined” MG 34 lacked, especially in themud and snow of the Russian front). Subsequently, it was officially adopted as the MG 42, and production commenced later the same year.
 In general terms, the MG 42 was a great success. It fulfilled the roles of a light machine gun on a bipod, a medium machine gun (on a newly developed Lafette 42 tripod), and an anti-aircraft machine gun, mounted in single and twin installations, ground and vehicle-mounted. It was relatively inexpensive to make and required less raw materials than the MG 34, and it was simple to maintain and use. On the minus side, it had a somewhat excessive rate of fire, usually quoted as 1200 rounds per minute, although German WW2 era manuals listed it as 1500 rounds per minute (25 rounds per second).This rate of fire resulted in excessive consumption of ammunition and rapid overheating. While the extremely rapid barrel change procedure allowed for sustained fire, the resulting accuracy left something to be desired; excessive vibration from recoil, combined with a short sight radius, resulted in degraded long range accuracy compared with earlier MG 34 and,especially, the heavy MG 08 Maxim guns. Nonetheless the MG 42 was an impressive and fearsome weapon, known among Allied soldiers as“Hitler’s saw”, for the sound of the firing which resembled the sound of a giant mechanical saw.
 After the WW2 this weapon, unlike other wartime designs, lived on, as in 1958, the FRG (WestGermany) re-instituted its official armed force, known as the Bundeswehr. Since the core of the Bundeswehr was formed of WW2 veterans, it was logical to adopt weapons which were already proven and familiar to the troops; and the MG 42 was one of such weapons. It was,obviously, chambered for a ‘non-NATO’ cartridge, but this was only a minor issue, as the 7.62x51 NATO and 7.92x57 Mauser shared the same cartridge base diameter, and were somewhat similar in ballistics. The real problem, however, was that Germany had lost most manufacturing facilities for the MG 42, so the newly reestablished Rheinmetall concern had to install production facilities from the ground up. The production documentation for original MG 42 machine guns was obtained from Grossfuss company and transferred to Rheinmetall (German government had to pay significant royalties to Johannes Grossfuns for manufacturing rights). Since the preparation for manufacture took sometime, the FRG purchased some ex-Wehrmacht MG 42 weapons from other countries. Those guns were converted to 7.62 NATO by Rheinmetall and officially designated MG 2. The newly produced MG 1 guns went through a number of modifications, which resulted in the definitive MG 3 version,which still is rather close in design to the war-time MG 42, although made to much higher standards of fit and finish. The simplicity, low manufacturing cost and high effectiveness of the MG 3 attracted several other countries, which either bought the guns from Rheinmetall (such as Denmark), or obtained manufacturing licenses and build (or at least have built in the past) the same guns domestically (such as Italy, Iran, Turkey, Pakistan and Yugoslavia). In total, at least twenty armies have used or still are using the MG 3 and its versions.It must be noted that in some countries these guns were used under their "commercial" Rheinmetall designation MG 42/59.
The MG 42is a short-recoil operated, air cooled, belt fed weapon which fires from an open bolt. The barrel is quick-removable, and can be replaced in less than six seconds by a properly trained crew, although an asbestos glove is required to remove the hot barrel. The action of the weapon is operated by the recoil of the locked barrel, assisted by a muzzle booster which uses pressure from the muzzle blast to increase the recoil impulse. Locking is achieved by a pair of rollers, which are forced outwards from the sides of the bolt head to engage cuts in the barrel extension. Locking (outward) movement of the rollers is controlled by the wedge-shaped front part of the bolt body; unlocking(inward) movement of the rollers by the cams made in the receiver. This is a simple and solid system which minimizes the length of parts that are under stress upon discharge, and also minimizes the strain on the receiver. On MG 3 machine guns, two types of bolts are available, with standard weight (about 650 gram) for fast rate of fire and with heavyweight (about 900 gram) for slow rate of fire. It must be noted that those bolts also are used along with different return springs.
 The receiver and barrel jacket are made in one unit, and formed from a sheet of rolled steel,cut to shape by pressing and stamping, and then welded and pinned to form a gun housing of generally rectangular cross-section. The front part of the housing serves as a barrel jacket and has a number of oval cooling slots at all sides except the right. The right side of the jacket has one long slot which is used to remove the barrel. The barrel is held in place by a hinged lock, located at the rear of the opening in the right side of the jacket. To remove the barrel, the operator must first lock the bolt in the open position (cock the weapon), and then turn the barrel lock to the right and forward. This will release the barrel and bring its breech area out of the jacket, so it can be grabbed (using the issued asbestos glove or other heat insulation means if the barrel is hot) and pulled back and out of the jacket. The new barrel is then inserted all the way forward and lock then is snapped into place, bringing the barrel into alignment with the action.
 The gun is fed using belts only. Feed direction is from the left to right;the feed is of the one-stage, push-through type. The belt is same as for the MG 34, with steel links with open pockets, assembled into non-disintegrating 50-round lengths. The same MG 34 type “Gurttrommel”50-round drum-type belt containers can be used with the MG 42, and a new type of lightweight plastic 50-round belt container was developed in West Germany by HK and is now issued with MG 3 guns. The belt feed is operated by the reciprocating bolt which has a roller at the top of its body. This roller engages the cam track in the oscillating lever, located in the top-opening feed cover. The lever operates the belt pawls in two steps, on both opening and closing movement of the bolt, resulting in a smooth and positive feed. This two-step belt traction is particularly useful because the high rate of fire results in high-speed belt movement, and this system reduces the strain put on both the feed unit and belt links. Current production MG 3 guns can fire either non-desintegrating or desintegrating belts.
 The trigger unit is ofrelatively simple design, and permits for automatic fire only. The manual safety is of the cross-bolt, push button type, located at the top of the pistol grip. The charging handle is located at the right side of the receiver, and is separated from the bolt group (it does not move when gun is fired). Each MG 42 was issued with an integral, adjustable bipod attached near the muzzle; MG 3 guns may have two points for bipod attachment, one near muzzle and another near the center of the gun. In the medium role, the MG 42 was used from the Lafette 42, a complicated foldable tripod with buffered cradle. A wide number of tripods is available for MG 3 guns,as produced in several countries.
  The standard sights are open, fully adjustable, and mounted on foldingbases. The universal tripod has provisions for mounting telescopic sights for long range and indirect fire missions.

Minggu, 10 Maret 2013

STEN submachine guns (Great Britain)

STEN Mk.III (STEN Mark 3) submachine gun.

STEN Mk.I (STEN Mark 1) submachine gun, with magazine removed.

STEN Mk.II (STEN Mark 2) submachine gun.

STEN Mk.IIS (STEN Mark 2 Silenced) submachine gun.

STEN Mk.IV (STEN Mark 4) submachine gun.

STEN Mk.V (STEN Mark 5) submachine gun.

STEN Mk.VI (STEN Mark 6 silenced) submachine gun.

Caliber 9x19mm 9x19mm 9x19mm 9x19mm
Weight, empty  3,26 kg  3,48 kg  3,18 kg 3,86 kg
Length 895 mm 900 mm 762 mm 762 mm
Barrel length 196 mm 90 mm 196 mm 196 mm
Rate of fire 550 rounds per minute 450 rounds per minute 550 rounds per minute 600 rounds per minute
Magazine capacity 32 rounds 32 rounds 32 rounds 32 rounds
Effective range 150-200 meters 50-100 meters 150-200 meters  150-200 meters

The STEN name came out of names of the designers (R. V. Shepard and H. J. Turpin) and from the factory where they worked (Enfield arsenal). It was one of the most crude and ugly and simply, but effective submachine guns of the WW2. Almost 4 millions of STEN guns of different versions were made between 1941 and 1945. STEN guns were made not only in Royal Small Arms factory in Enfield; other makers included famous British gunmaking company of the time BSA Ltd, as well as Royal Ordnance Arsenal in Fazakerly, England, and Long Branch Arsenal in Canada.
The first STEN, STEN Mk.I (full official name was 9mm STEN Machine Carbine, Mark 1), was developed in mid-1941. It was blowback operated, automatic weapon that fired from the open bolt. Trigger unit permitted for sigle shots and full automatic fire, controlled by the cross-bolt type button, located in front and above trigger. The tubular receiver and the barrel shroud were made from rolled steel. The gun was fed from left side mounted box magazines. The stock was of skeleton type, made from steel. Sights were fixed, pre-adjusted for 100 yards distance, peep hole rear and blade front. The Mk.1 featured spoon-like muzzle compensator. Some guns featured small folding forward grip. Total production of Mark 1 and slightly modified Mark 1* STEN machine guns was about 100 000.
The STEN Mk.II submachine gun was most widely made gun in entire STEN series, with about 2 millions of Mark 2 being made during the war. It was slightly smaller and lighter than Mk.I. Basic design was the same as Mark 1, with omission of all wooden parts of Mk.I and shorter barrel jacket, which made the Mk.II lighter than its predecessor. Magazine housing could be rotated for about 90 degrees down to close feed and ejection apertures during transportation and off-battle carry (this feature caused much troubles as the rotary unit was not very durable and magazine could be misaligned during combat, what led to feed malfunctions and jams). Another source of problems was magazine spring, so magazines were routinely loaded with 28-30 rounds instead of "full capacity" 32 rounds to reduce strain on the magazine spring.
Some Mk.II STEN guns were manufactured with integral silencers for undercover operations and were marked as Mk.II(S). These guns had shortened barrels enclosed into integral silencer. The silencer was rather effective so most audible sound when firing Mk.IIS was the clattering of the bolt moving back and forth in the receiver. Contemporary manuals advised that Mk.IIS submachine gun was to be fired in semi-automatic mode; the ful-automatic fire was reserved for emergency situations, as it decreased the service life of  silencer significantly.
The STEN Mk.III was modification of Mk.I. The major change was that the receiver and the barrel shroud were made from single tube (wrapped from sheet-steel and welded at the top) that extended almost to the muzzle. Another changes included fixed magazine housing for improved reliability and small finger guard in the front of the ejection port. Internally, Mk.III was similar to Mk.I and has same variety of skeleton stocks. Mk.III first appeared in 1943.
The STEN Mk.IV was made in experimental form only, and did not entered the production. It was originally intended for airborne troops.
The STEN Mk.V submachine gun was an attempt to made Mk.II a more "good looking'" gun. Being internally the same as Mk.II, the "STEN Mk.V machine carbine" featured wooden buttstock and rear pistol grip, new front sight and bayonet mount. Early Mk.V's also featured wooden front grips, but these were prone to breakage and thus were removed soon. STEN Mk.V appeared in 1944 and remained in service until the early 1960s', and then replaced by Sterling submachine guns.