|Place of origin||Germany|
|Used by||see Users|
|Manufacturer||Heckler & Koch|
|Mass||1,200 grams (42 oz) loaded|
Battery pack 700 grams (25 oz)
|Length||200 millimetres (7.9 in)|
|Width||60 millimetres (2.4 in)|
|Cartridge||7.62×36mm, about 100 millimetres (3.9 in) long, miniature solid-fuelled rocket with fins|
|Effective firing range||30 metres (98 ft) in air,|
10 to 15 metres (33 to 49 ft) underwater
|Feed system||5 rounds, each in a barrel|
|Sights||14.6 centimetres (5.7 in) between sights|
The HK P11 is a Heckler & Koch pistol designed as an underwater firearm that was developed in 1976. It has five barrels and each fires a 7.62 X 36mm dart electrically. Loading is by means of a five-round case. The design resembles that of a pepper-box firearm.
Since ordinary-shaped rounds are inaccurate and have a very short range when used underwater, this pistol fires steel darts. It has five barrels, each of which is loaded with a cartridge, giving the gun a pepper-box appearance, and it is electrically ignited from a battery pack in the pistol grip.
After firing all five cartridges, the barrel unit must be sent back to its manufacturer for reloading. It is very similar to its predecessor, the Mk 1 Underwater Defense Gun. In the past, Heckler & Koch has denied knowledge of its existence.
This firearm is somewhat bulkier than its Soviet counterpart, the SPP-1 underwater pistol, but it has five barrels, as opposed to the Soviet firearm which has four. However, the SPP-1 does not need to be sent back to the manufacturer to be reloaded.
- Germany: German commando frogmen.
- Italy: Italian Navy COMSUBIN.
- Malaysia: Pasukan Khas Laut (PASKAL) of the Royal Malaysian Navy
- United Kingdom: Special Boat Service of the British Royal Navy.
- SPP-1 underwater pistol – Soviet four-barreled underwater dart pistol
- Underwater firearm – Firearms that can be effectively fired underwater
- Electronic firing
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- HKPRO: The HK P11
- Securityarms: Heckler & Koch P11 Underwater Pistol
- Modern Firearms: Heckler Koch HK P11 underwater pistol