

One of the most thoroughly tested handguns in history, the MK23/MARK 23 project originated in 1991 when HK began development for the U.S. Special Operations Command, the unit that directs the activities of America’s most elite military units, including the NAVY SEALS and the Army Special Forces. Following stringent comparative trials, on May 1st, 1996 the Mk23 was adopted as a service pistol under the designation MK23 MOD.O.
Among others the following tests had to be passed successfully:
The frame mounted de-cocking lever, separate from the ambidextrous safety lever, allows the hammer to be lowered safely and quietly. When the hammer is down, the ambidextrous frame mounted safety lever is locked in fire position so that the pistol is always ready for Single Action operation. During testing, the USP had to meet the most stringent operational and accuracy requirements ever demanded of a combat handgun. Endurance testing demonstrated a service life of over 30,000 rounds of + P ammunition. To meet the reliability requirement, the pistol had to demonstrate a minimum of 2000 mean rounds between stoppage (MRBS). All pistols in the test exceeded the 2000 MRBS with an average of 6000 rounds.
In more than 450 accuracy test firings from a precision firing fixture, MK23 pistols far exceeded the US Government requirement, averaging under 37 mm.
| Specifications | |
| Caliber | .45 AUTO |
| Principle of operation | Recoil operated weapon with modified Browning locking system and recoil buffer system |
| Dimensions | .45 AUTO |
| Overall length | 9.65" |
| Overall height | 5.90" |
| Overall width | 1.54" |
| Barrel length | 5.87" |
| Sight radius | 7.68" |
| weight | |
| Without magazine | 2.43 lb |
| other specifications | |
| Magazine capacity | 12 Cartridges |
| Single Action (SA) trigger pull |
5.17 lbs |
| Double Action (DA) trigger pull |
11.47 lbs |
| Sights | Fixed (Open square notch rear sightwith contrast points) |
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Safety lever The MK23 has an ambidextrous safety lever. Even in the “Safe” position, the slide may be operated in order to load or to unload. The MK23 can only be put on “Safe” in cocked condition. |
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