Heckler & Koch MP5

The Heckler & Koch MP5 is currently one of the most widely used submachine guns in the world, having been adopted by numerous law enforcement agencies and special forces groups due to the reliability of the sub-machine gun. In the 1990s, Heckler & Koch developed the Heckler & Koch UMP, the MP5′s successor, though both remain in production.

Heckler & Koch, after the success of the G3 automatic rifle, developed a family of small arms consisting of four types of firearms (all based on a common G3 design layout and operating principle), where the first type was chambered in 7.62x51mm NATO, the second—using the 7.62x39mm M43 round, third—the intermediate 5.56x45mm NATO caliber and the fourth type—chambering the 9x19mm Parabellum pistol cartridge. The MP5 was created within the fourth group of firearms and was initially known as the HK54.

Development on the new sub-machine gun began in 1964 and scarcely two years later the MP5 was adopted by the German Federal Police, border guard and army special forces.

The MP5 is manufactured under license in several nations including Greece (formerly at EBO – Hellenic Arms Industry, currently at EAS – Hellenic Defense Systems), Iran (Defense Industries Organization), Mexico (SEDENA), Pakistan (Pakistan Ordnance Factories), Saudi Arabia, Sudan (Military Industry Corporation), Turkey (MKEK), and the United Kingdom (initially at Royal Ordnance, later diverted to Heckler & Koch Great Britain).

The primary version of the Heckler & Koch MP5 family is the MP5A2, which is a lightweight, air-cooled, selective fire delayed blowback operated 9x19mm Parabellum weapon with a roller-delayed bolt. It fires from a closed bolt (bolt forward) position.

The fixed, free floating, cold hammer-forged barrel has 6 right-hand grooves with a 1 in 250 mm (1:10 in) rifling twist rate and is pressed and pinned into the receiver.

Variants

The MP5A2 has a fixed stock (made of a synthetic polymer), whereas the compact MP5A3 has a retractable metal stock.
In the early 1970s HK introduced a conversion kit for the MP5 that enables it to use sporting ammunition (.22 LR). This unit consists of a barrel insert, a bolt group and two 20-round magazines. This modification reduces the cyclic rate to 650 rounds/min.

The MP5A2 and MP5A3 are available with optional 4-position trigger groups; these are known as the MP5A4 and MP5A5 respectively. The trigger groups are marked with bullet pictograms rather than letters or numbers (each symbol represents the number of bullets that will be fired when the trigger is pulled and held rearward with a full magazine inserted in the weapon) and are fully ambidextrous (the selector lever is present on each side of the trigger housing). The additional setting of the fire selector, one place before the fully automatic setting, enables a two or three-shot burst firing mode.

H&K offers dedicated training variants of these weapons, designated MP5A4PT and MP5A5PT (PT – Plastic Training), modified to fire a plastic 9x19mm PT training cartridge produced by Dynamit Nobel of Germany. These weapons operate like the standard MP5 but have a floating chamber and the bolt lacks both rollers to function properly when firing the lighter plastic projectiles. To help identify these weapons blue dots were painted on their cocking handles and additional lettering provided. The PT variant can be configured with various buttstocks and trigger groups and was developed for the West German Police and Border Guard.

The modular design of the MP5 offers multiple trigger groups: three-position “SEF” fire selector (positions: “S”-safe, “E”-semi automatic, “F” fully automatic. Located on left of receiver only); three-position fire selector (positions: safe, semiautomatic and a 2 or 3-round burst; selector lever is ambidextrous and its settings are marked with pictograms); four-position fire selector (positions: weapon safe, single fire, 2 or 3-round burst, full auto; ambidextrous selector; selector settings marked with pictograms); two-position fire control group (positions: weapon safe, single fire only; ambidextrous selector lever with pictograms) and a three-position fire selector group – the so called “Navy” trigger (settings: weapon safe, semi-automatic, fully automatic fire; ambidextrous selector lever; selector settings marked with bullet symbols again).

A variant with the last trigger group designated the MP5-N (N – Navy) was developed in 1986 for the United States Navy. This model has a collapsible stock, a tritium-illuminated front sight post and a 225 mm (8.9 in) threaded barrel for use with a stainless steel sound suppressor made by Knight’s Armament Company together with suppressed subsonic ammunition.