The HK MP5 10a2 is a product-improved variant of the HK MP5 chambered for the 10mm Auto round. The increased stopping power of the heavier round is offset by increased recoil. The MP5/10 is designed to meet the ever increasing call by U.S. Law Enforcement for a compact, accurate and reliable submachine gun chambered for a cartridge with increased terminal effects on target. The 10mm Auto cartridge provides up to twice the muzzle energy of the standard 9mm parabellum NATO cartridge, and still is easily controllable due to the unique roller-locked bolt system employed throughout the HK line of weapons. This perfect combination of weapon and cartridge puts the firepower, penetration and hard hitting potential of a .45 ACP Thompson SMG into a package identical in size and weight to the 9mm MP5.

The MP5/10 will come standard with HK's ambidextrous trigger group providing for single, 3-round burst and sustained (full automatic) fire modes. Optional trigger groups, including any combination of the above modes of fire, will also be available. The safety/selector switch is easily accessible by right or left handed operators and does not require operators to change their firing grip to take the weapon off "safe".

A newly designed translucent synthetic magazine allows the user to see the immediate status of the rounds remaining in the magazine. These magazines snap together without the need of an accessory clamp, providing the operator with sixty rounds of available firepower right on the weapon. Using a specially developed high strength polymer, these are magazines 30% lighter and impervious to corrosion.

The HK MP5 10a2 can be fitted with a sound suppressor giving a nice mix between power and silence, although the suppression is not quite as complete as an integral option like that used by the MP5SD range.