Heckler & Koch MP5/10

In 1991, Heckler & Koch introduced MP5A4 and MP5A5 submachine guns chambered for the 10mm Auto cartridge. Designated the MP5/10, this gun is nearly identical to the other MP5 variants of Heckler & Kochs submachine guns except for its chambering and a very slight increase in weight. Nevertheless the gun is readily recognizable by its straight, transparent 30-round plastic magazine. One other departure from the standard MP5 design is a bolt catch located on the left side of the receiver above and to the front of the selector.

The MP5/10 is normally seen with the H&K "4-Position Group" with single, semiauto, three-round burst, and auto positions. Like many other burst mechanisms, the three-round burst in the 4-Position Group sometimes fires only one or two shots if the trigger is pulled and quickly released before the cycle is completed.

Heckler & Koch's submachine guns have proven to be one of the company's more popular weapon groups worldwide. The submachine gun was originally designed the "HK54." However the "MP5" (Machine Pistol number 5) designation used by the West German Border Police has been the name that "stuck" with the firearm since this was the first major purchaser of the submachine gun. As the MP5 name became more and more popular, Heckler & Koch soon followed suit and redesignated its submachine gun as the "MP5" in its catalogs and literature.

The standard 4x24 Heckler & Koch detachable scope fits the MP5 including the MP5/10 as do the company's "1003 Aiming Projector" which creates a narrow beam of intense light along the line of fire from the gun. The 55-watt Halogen lamp is energized by a 12-volt battery coupled to a button, permitting locating and identifying targets; the manufacturer claims that an experienced shooter using the spot for aiming can hit targets of about four inches in diameter at distances of 75 meters. The bright light can also be employed to dazzle targets by switching the light on for a short period during which several single shots or bursts are fired. The light is then switched off briefly, after which the procedure is repeated, the dazzling effect giving a tactical advantage to the user.

In the early 1990s, Heckler & Koch introduced a small laser sight for its MP5s. Designated the "HK 100 Laser Aimer," this sight mounts in the front of the charging lever tube, just below the front sight. A momentary switch is placed on the handguard, permitting switching the laser on briefly to acquire a target. For those using night vision goggles, the company's "INKAS" infrared laser sight might also be employed on the MP5. Adapter mounts to place military night vision scopes are also available for use with the MP5 submachine guns.

Unlike many other modern submachine guns that operate with blow-back action and fire from an open bolt, the MP5/10 fires from a closed bolt in the same manner that its G3 rifle counterpart does. The bolt also uses the locking rollers of the rifle for delayed blow-back, permitting a much lighter rifle. Firing from a closed bolt does increase the chance of cookoffs during long strings of automatic fire; but many special force units prefer the MP5 because of the inherent accuracy firing from a closed bolt offers. This greater accuracy is possible due to less movement of the firearm. When the first shot is fired, only the hammer travels forward when the trigger is pulled, rather than a heavy bolt slamming forward as is the case with guns firing from an open bolt.

The delayed recoil roller blocks incorporated into the MP5/10 does away with the need for a heavy bolt as well as a gas system. This arrangement also permits guns to have their barrels cut down to extremely short lengths while still operating reliably. Because the roller system doesn't turn or otherwise loosen the cartridge before it is extracted (unlike most gas-operated firearms), fluted cuts run inside of the barrel's chamber. During the moment of firing, a small amount of gas travels alongside the cartridge thereby "floating" it on a cushion of hot vapor for easy extraction.

The MP5 submachine guns first made their public appearance in 1966 literature from Heckler & Koch. Generally the "MP5" designation is the standard stocked submachine gun. When the retractable stock was placed on the receiver, the original submachine guns were designated as "MP5A1s".

Minor modifications were made to the basic design of the submachine guns in 1987. The new fixed stock version then became the "MP5A2" while the retractable stock version became the "MP5A3." That said, the MP5/10 is generally seen with the telescoping stock. The MP5/10 also has the newer-styled handguard which is smooth and tapers to the front of the gun rather than the older, non-tapering checkered handguard.