The HK 45 is a modern pistol of German origin, although the design was mainly carried out in the USA. It was developed to meet the US Army requirements for a .45 ACP pistol in the Joint Combat Pistol program, which was suspended indefinitely. The name HK 45 is derived from the sole caliber in which this pistol is available.
The HK 45 uses a mixture of design elements from the USP and P30 pistols. The internal mechanism of the HK 45 is derived from the higher quality USP models that feature an O-ring barrel, such as the USP Tactical. The exterior and ergonomics are derived from the P30, as is shown by the ergonomic grip with exchangeable backstraps and ambidextrous slide release. The HK 45 is recoil operated with modified Browning locking system and recoil buffer system. A Picatinny accessory rail is present.
The HK 45 is a semi-automatic pistol that fires the powerful .45 ACP from a 10 round magazine. Due to the design and production quality the accuracy is reportedly very good. Accuracy is claimed to be on par with custom made M1911's. Both the full size and the compact model can be fitted with a threaded barrel to accept silencers.