MP5.

Often, weapons become associated with the forces that wield them: their role and alignment help shape their identity. Lawful good through and through - this is a gun for the good guys: The MP5. So, how did it earn its heroic status? What makes it a perfect fit for a counter-terror role? And what's the deal with the slap? The MP5 is a German weapon, manufactured by Heckler & Koch. H&K were founded in 1949, directly in the wake of World War 2. The company took its name from two of its three co-founders: all of whom were former Mauser engineers: Alex Seidel, Edmund Heckler and Theodor Koch. At first, they manufactured machine tools and precision metal parts - but in 1956 the West German government put out a tender for a new rifle for the Bundeswehr. H&K put forward the G3 design, based on a rifle designed by former Mauser engineers at CETME, a Spanish technical institute. Their bid proved successful, and H&K developed a number of G3-derived designs to fit different roles - with the MP5 amongst them. Originally known as the HK54, work began on the new SMG in 1964. It fires the 9×19mm Parabellum round, the standard NATO pistol calibre. Original magazines were straight, but a slight revision in 1977 gave the weapon its distinctive and slightly curved 30-round mag. Like its parent G3 design, the MP5 has a roller-delayed blowback mechanism - a simplistic but effective enough action that has roots in German prototypes made near the end of the war. There are quite a few MP5 variants available: from the original HK54, also known as the MP5A1; the fixed stock MP5A2 and A4; retractable stock MP5A3; and sliding stock MP5A5. The MP5K - or Kurz - is a shortened variant, pared down into the smallest package possible: The MP5SD variants boast an integral suppressor, for covert use; and there are larger-calibre variants too: such as the MP5/10, which fires powerful 10mm Auto rounds; and the MP5/40, which fires .40 Smith & Wesson. A flexible and configurable weapon, then - and one that has found favour with a large number of police and special forces units.

In 1980, one event in particular secured the MP5's iconic status: a siege on the Iranian Embassy in London.

6 terrorists, 26 hostages, a densely-populated urban location and a live television feed: it was a very tense situation with an awful lot on the line. On the sixth day of the siege, a hostage was killed. This prompted immediate action by the British Special Air Service - under the codename Operation Nimrod.

17 minutes after their first breach, 5 terrorists were killed, the final captured - and all remaining hostages were rescued. The mission's success reinforced the SAS's reputation as a deady special operations force: and these events served as the perfect advertisement for the SMG they used. Its proven track record, and suitability for the close-range fighting typical of urban terror operations, make it a fitting choice for any counter-terror role - and a must-have inclusion for any games that depict such forces. The SAS' legendary live-fire exercises in the Killing House are depicted in the tutorial of Call of Duty 4: in which you drill the following mission's plan with plywood simulacrum. The MP5's presence here is true-to-life, and the game shows a recreation of the real training exercises that the SAS would have undertaken in preparation for the embassy siege. The MP5 sees prime placement in the armouries of tactical shooters, then: and it's a flagship weapon of the Rainbow Six series. When it comes to tackling a terrorist threat, there's nothing better for the task. One quirk that crops up during the MP5's reload is the infamous 'HK slap': an open-handed tap on the cocking lever after inserting a fresh magazine, sending the bolt forward and chambering a round. It might seem reckless to smack your weapon, but it's actually recommended procedure: a softer approach might not drive the bolt home properly. Besides, the MP5 is a working weapon - and one that can withstand a little rough-housing. The 'slap' isn't unique to the MP5 - but it's a cool move that has helped to bolster its iconic identity through fiction as well as fact. Its distinctive on-screen presence and association with heroic action makes it a prominent choice in cinema. The weapon has turned up in hundreds of films - normally seen in the hands of the good guys, but sometimes revealing a more impetuous side. With notable appearances in Die Hard 2 and The Matrix, the weapon appears outside its counter-terror role in games inspired by classic action movies. Games like Max Payne and Modern Warfare 2 indulge a more brash side of the SMG: far from the tightly controlled discipline of well-trained special forces, the MP5 can also employ spray and pray tactics. It might waste ammunition, but it looks good on screen - and more empty mags mean more stylish reloads, complete with the slap. Today, there are a number of more modern SMGs and personal defence weapons vying to replace the fifty-year-old MP5 design. H&K themselves even offer two alternatives: the more modern and larger-calibre UMP-45, and the armour-piercing power of the diminutive MP7: but the classic 9mm SMG still reigns supreme: well-loved by those who wield it, and with ubiquitous use by police forces worldwide. A legendary submachine gun that earned its reputation through a baptism by fire. Always cool under crisis, its the perfect counter-terror weapon: The MP5. Confident. Force for order. Terrorist's bane. Thank you very much for watching - Iconic Arms will return: and until next time, farewell.