Heckler & Koch MP7

The MP7 is a German Personal Defence Weapon (PDW) manufactured by Heckler & Koch (H&K) and chambered for the HK 4.6×30mm cartridge. It was designed with the new cartridge to meet NATO requirements published in 1989, as these requirements call for a personal defense weapon (PDW) class firearm, with a greater ability to defeat body armor than current weapons limited to conventional pistol cartridges. The MP7 went into production in 2001. It is a direct rival to the FN P90, also developed in response to NATO's requirement. The weapon has been revised since its introduction and the current production version is the MP7A1.

The proliferation of high-quality body armour has begun to make guns that fire pistol ammunition (such as Heckler & Koch's earlier MP5 submachine gun or USP pistol) ineffective. In response to this trend, Heckler & Koch designed the MP7 (along with the now cancelled UCP pistol, which uses the same ammunition) to penetrate body armor, but small enough to be used in place of either a pistol or a submachine gun.

Design details
The MP7 uses a short stroke piston gas system as used on H&K's G36 and HK416 assault rifles, in place of a blowback system traditionally seen on sub-machine guns including those by H&K. The 4.6x30mm ammunition is virtually exclusive to the gun (save for the now cancelled Heckler & Koch UCP and a planned variant of the Brügger & Thomet MP9) and also offers low recoil. This ammunition is unique among submachine guns in that the bullet is made almost entirely of a hardened steel penetrator instead of softer copper or lead.

The weapon allows a conventional 20-round, 30-round, or 40-round box magazine to be fit within the pistol grip (the 20-round magazine being comparable in size to a 15-round 9mm magazine, while the 40-round magazine compares to a 30-round 9 mm magazine). The weapon features an ambidextrous fire selector, bolt catch lever and magazine release. It has an extendable stock and a folding front grip; it can be fired either one-handed or two-handed. It is compact and light, due to the use of polymers in its construction.

Ammunition
The MP7's specially designed armour piercing (AP) high velocity rounds allow copper plated solid steel projectile (DM11), alloy plated steel jacket projectile (DM21) or copper alloy jacketed lead core projectile (Fiocchi FMJ ZP). Standard AP high velocity DM11 (Ultimate Combat) round with a 2.0 g (31 gr) projectile has a muzzle velocity of 720 m/s (2,362 ft/s), which is nearly as high as that of a .223 Remington round, and has a muzzle energy of 506 J (373 ft-lbf). The DM11 round penetrates the NATO CRISAT target (20 layers of kevlar with 1.6 mm titanium backing) even at 200 m. The round has a small diameter, allowing for redoubling penetration capability and high capacity in a very small magazine.

VBR of Belgium produces a 4.6x30mm 2-part controlled fragmenting projectile that is claimed to increase the content of the permanent wound cavity and double the chance to hit a vital organ. Heckler & Koch claims that the CPS Black Tip ammunition made by Fiocchi has a muzzle energy of approximately 525 J, which would be comparable to 9x19mm Parabellum rounds.

Variants

 * PDW: The first prototype shown in 1999 was designated the 'PDW' (Personal Defence Weapon). It had a short Picatinny rail on the top and a smooth pistol grip surface.
 * MP7: In 2001 it was named the 'MP7' and went into production. It included a full length Picatinny rail, a thick curved stock and an anti-slide surface on the pistol grip much like the HK USP. It also featured folding iron sights mounted on the Picatinny rail and the button to fold the foregrip was made larger for easier operation.
 * MP7A1: In 2003 its designation was changed to 'MP7A1' and featured a redesigned pistol grip with a different surface and curved shape, a smaller stock with a straight buttpad, side mounted picatinny rails as standard and the folding iron sights were made more compact. The weapon was made slightly longer, but because the stock was shortened, the overall length did not change. The stock is also able to be locked into 3 positions. Recent MP7A1 models have a trigger safety similar to a Glock pistol; the middle section of the trigger must be pulled first before the outer part will move. This helps to stop accidental discharges if the trigger is bumped.
 * MP7-SF: Semi-automatic only variant of MP7. Currently used by Ministry of Defence Police in United Kingdom.

Accessories
The weapon features a full-length, top-mounted Picatinny rail that comes as standard with folding fore and rear iron sights attached. When the sights are folded flat, they resemble simple open sights. Folded up, they feature aperture sights. The sights can easily be removed by loosening a single screw and lifting them off. It can fit additional rails on the sides of the barrel, which allow it to mount commercial optical sights (telescopic and red dot sights), laser aiming modules (LAM), and tactical flashlights. The MP7 can also accept a suppressor. The tailor-made suppressor for the MP7 does not interfere with its accuracy or rate of fire.