Tuesday, March 24, 2009

CZ_75_Automatic_With Hand Grip









Ak-105









M203 grenade launcher





The M203 is a single shot 40 mm grenade launcher that attaches to a number of popular assault rifles, but was originally designed for the U.S. M16 and its variant, the M4 Carbine. In the U.S. military, when a rifle or carbine is equipped with the launcher, both weapons are collectively referred to as an M203. The launcher can also be mounted onto a C7, a Canadian version of the M16 that uses an optical scope instead of an iron sight, and requires the bottom handguard on the rifle to be removed in order to mount the launcher. Stand-alone variants exist as do versions capable of being used on many other rifles. The device attaches under the barrel and forward of the magazine, the trigger being just forward of the rifle magazine. The rifle magazine functions as a hand grip when firing the M203. A separate sighting system is added to rifles fitted with the M203, as the rifle's standard sights are not matched to the launcher. The version fitted to the Canadian C7 has a sight attached to the side of the launcher, either on the left or right depending on the user's needs.

Heckler & Koch G3









The G3 is a 7.62mm automatic rifle developed in the 1950s by the German armament manufacturer Heckler & Koch GmbH (H&K) in collaboration with the Spanish state-owned design and development agency CETME (Centro de Estudios Técnicos de Materiales Especiales).[1]

Development









The origin of this rifle can be traced back to the final years of World War II when Mauser engineers at the Light Weapon Development Group (Abteilung 37) at Oberndorf am Neckar designed the MKb Gerät 06 (Maschinenkarabiner Gerät 06 or "machine carbine instrument 06") prototype assault rifle chambered for the intermediate 7.92x33mm Kurz cartridge, first with the Gerät 06 model using a roller-locked short recoil mechanism originally adapted from the MG 42 machine gun but with a fixed barrel and conventional gas-actuated piston system.[2] It was realized that with careful attention to the mechanical ratios, the gas system could be omitted.[3] The resultant weapon, the Gerät 06H (the "H" suffix is an abbreviation for halbverreigelt or "half-locked") was assigned the designation StG 45(M) (Sturmgewehr 45(M)) but was not produced in any significant numbers and the war ended before the first production rifles were completed.[4]
The German technicians involved in developing the Sturmgewehr 45 continued their research in France at CEAM. The StG45 mechanism was modified by Ludwig Vorgrimler and Theodor Löffler at the Mulhouse facility between 1946 and 1949. Three versions were made, chambered in .30 Carbine, 7.92x33mm Kurz as well as the 7.65x35mm cartridge developed by Cartoucherie de Valence and adopted in 1948. A 7.5x38mm cartridge using a partial aluminium bullet was abandoned in 1947. Löffler's design, designated the Carabine Mitrailleuse Modèle 1950, was retained for trials among 12 different prototypes designed by CEAM, MAC, and MAS. Engaged in the Indochina War and being the second NATO contributor, France canceled the adoption of these new weapons for financial reasons.
In 1950, Vorgrimler moved to Spain where he created the LV-50 rifle chambered in the intermediate 7.92x33mm Kurz cartridge and later, the proprietary 7.92x40mm CETME M53 round.[5] At this point, the rifle was renamed the Modelo 2. The Modelo 2 attracted a lot of attention from the West German Border Guards (Bundesgrenzschutz), which sought a new service rifle. Not willing to accept a cartridge outside of the NATO specification, the Germans asked CETME to develop a 7.62 mm version of the rifle. The resulting CETME rifle Model A was chambered for the 7.62x51mm CETME cartridge which has identical chamber dimensions but a reduced-power load compared to the 7.62x51mm NATO round. Further development of the rifle with input from HK produced the CETME Model B which received several modifications including the ability to fire from a closed bolt in both semi-automatic and automatic firing modes, a new perforated sheet-metal handguard (the folding bipod had been the foregrip in previous models), improved ergonomics and a slightly longer barrel with a rifle grenade launcher guide. In 1958, this rifle was introduced into service with the Spanish Army as the Modelo 58, firing the 7.62x51mm CETME round.
In 1956, the Bundesgrenzschutz canceled its planned procurement of the CETME rifles, adopting the FN FAL (G1) instead. However, the newly formed West German Army (Bundeswehr) now displayed interest and soon purchased a number of CETME rifles (7.62x51mm NATO chambering) for further testing. The CETME, known as the Automatisches Gewehr G3, competed successfully against the SIG SG 510 (G2) and AR-10 (G4) to replace the previously favored G1 rifle. In January 1959, the Bundeswehr officially accepted the CETME rifle. The West German government wanted the G3 rifle to be produced under license in Germany; purchase of the G1 had previously fallen through over FN's refusal to grant such a license. In the case of the G3, the Dutch firm Nederlandse Wapen en Munitiefabrik (NWM) held production and sales rights to the CETME design outside of Spain. To acquire production rights, the West German government offered NWM contracts to supply the Luftwaffe with 20 mm ammunition. Production of the G3 was then assigned to Rheinmetall and HK. The latter company already had ties to CETME, and had worked to further optimize the CETME rifle for use with the full-power 7.62x51mm NATO cartridge (as opposed to the downloaded CETME variant). In 1969, Rheinmetall gave up production rights to the G3 in exchange for HK's promise not to bid on MG3 production. Later in 1977, the West German government ceded ownership of G3 production and sales rights exclusively to HK.
Initial production G3 rifles differed substantially from more recent models; early rifles featured closed-type mechanical flip iron sights (with two settings), a lightweight folding bipod, stamped steel handguard, wooden buttstock (in fixed stock models) and a telescopic metal stock (in folding stock models).[5] The weapon was modernized during its service life (among other minor modifications it received new sights, a different flash hider, a plastic foregrip and stock), resulting in the current production variants, the G3A3 (with a fixed synthetic stock) and the G3A4 (telescoping metal stock). The rifle proved successful in the export market, being adopted by the armed forces of over 40 countries.[5] The G3 was and in some cases continues to be produced under license in: France (MAS), Greece (Hellenic Arms Industry), Iran (Defense Industries Organization), Mexico, Myanmar, Norway (Kongsberg Våpenfabrikk), Pakistan (Pakistan Ordnance Factories), Portugal (FBP), Saudi Arabia, Sweden (FFV), Thailand, Turkey (MKEK) and the United Kingdom (Royal Ordnance).[5]

Design details









The G3A3 (A4) is a selective-fire automatic weapon that employs a roller-delayed blowback operating system. The two-piece bolt assembly consists of a breech (bolt head) and bolt carrier. The bolt is partially locked in battery by two sliding cylindrical rollers that engage locking recesses in the barrel extension. The breech is unlocked when both rollers are compressed inward against camming surfaces driven by the rearward pressure of the expanding exhaust gases upon the bolt head. As the rollers move inward recoil energy is transferred to the locking piece and bolt carrier which begin to withdraw while the bolt head remains locked. As the bolt carrier clears the rollers, pressure in the bore drops to a safe level, the bolt head is unlocked and begins to recoil backwards at a velocity lower than that of the bolt carrier. The bolt also features an anti-bounce mechanism that prevents the bolt from bouncing off the barrel's breech surface. The spring-powered claw extractor is also contained inside the bolt while the lever ejector is located inside the trigger housing (actuated by the recoiling bolt).[5]
The rifle is hammer fired and has a trigger mechanism with a 3-position fire selector switch that is also the manual safety toggle that secures the weapon from accidentally discharging (fire selector in the “E” or “1” position – single fire mode, “F” or “20” – automatic fire, “S” or “0” – weapon is safe, trigger disabled mechanically). The weapon can be fitted with an optional 4-position safety/fire selector group illustrated with pictograms with an ambidextrous selector lever. The additional, fourth selector setting enables a 3-round burst mode of fire.[5]

A cut-away of the G3 roller-delayed locking mechanism.
The G3A3 (A4) uses either steel (260 g) or aluminum (140 g) double-stacked straight box magazines.
The firearm was equipped with iron sights that consist of a rotary rear drum and hooded front post. The rear sight, mechanically adjustable for both windage and elevation, has an open notch used to fire up to 100 m and three apertures used for: 200, 300 and 400 m.[5] The receiver housing has recesses that work with HK clamp adapters used to mount day or night optics.
The rifled barrel (contains 4 right-hand grooves with a 305 mm twist rate) is ended with a slotted flash suppressor which can also be used to attach a bayonet or serve as an adapter for launching rifle grenades. The barrel chamber is fluted, which assists in the initial extraction of a spent cartridge casing (since the breech is opened under very high barrel pressure).[5]
Standard accessories supplied with the rifle include: a detachable bipod (not included with rifles that have a perforated plastic handguard), sling, cleaning kit and a speed-loading device. Several types of bayonet are available for the G3, but with few exceptions they require an adapter to be inserted into the end of the cocking tube. The most common type features a 6 3/4 inch spear-point blade nearly identical with the M7 bayonet, but with a different grip because of its mounting above the barrel. A variant of this exists with an 9 1/4-inch blade that is completely double-edged like a dagger. A rather shoddily made Pakistani bayonet with a British-style bowie blade also exists, and one of the Eickhorn KCB77 variants fits the G3. The weapon can also mount a 40 mm HK79 under-barrel grenade launcher, blank firing adapter a straight blowback bolt (called a “PT” bolt, lacks the locking rollers) used for firing 7.62x51mm ammunition with plastic bullets, a conversion kit used for training with .22 LR ammunition and a sound suppressor (that uses standard ammunition).
Apart from the G3A3 and G3A4 HK also built: the G3A3ZF (essentially a G3A3 with a Hensoldt 4x24 optical sight), the accurized G3SG/1 rifle (hand-selected G3A3’s, equipped with an improved trigger, Zeiss telescopic sight with a variable 1.5-6x magnification and a cheek riser) and the G3K carbine which uses an HK33 handguard and a short barrel (reduced in length to the base of the front sight post), that is too short for use with a bayonet or rifle grenades.[5]
The G3 served as a basis for many other weapons, among them: the PSG1 and MSG90 precision rifles, the HK11 and HK21 family of light machine guns, a single-fire version known as the HK91, a sporterized model called the SR9 (designed for the civilian market) and the MC51 carbine, produced by the UK firm FR Ordnance International Ltd. for special forces. The MC51 weighs 3.1 kg (6.8 lb), has a folded overall length of 625 mm (24.6 in), a barrel length of only 230 mm (9.1 in), which produces a muzzle velocity of approx. 690 m/s (2,263.8 ft/s) and a muzzle energy of 2215 J. The MC51 was allegedly manufactured for the British SAS and SBS, who required a compact but powerful weapon, for situations in which the stopping power and armor piercing capabilities of 9x19mm Parabellum round were inadequate. Only 50 weapons were produced, and all were reportedly shipped to the UK special forces. Most of them were soon replaced by the Heckler & Koch HK53 carbine. Another UK-based company called Imperial Defence Services Ltd. absorbed FR Ordnance and continues to market the MC51 standard variant. In addition, a weapon similar to the MC51 called the M41 Offizier is produced by Schwaben Arms GmbH of Germany.[6]