The HK USP marks the first time Heckler & Koch has decided to incorporate many traditional handgun design features in a single pistol. USP's design is a rapt departure from the many exclusive, unique and ambitious legacy designs such as the P7's unique squeeze cocking mechanism, the P9S's precise roller delayed blowback operation, and the uncanny plastic frame and DOA trigger system in the VP70Z. The HK USP relies mostly on innovating traditional design features such as those of John Browning's M1911.
The result is a rare gun that is fast enough for defensive shooting, accurate enough for high levels of precision and capable of the withstanding heavy handed abuse from any type of ammo and for exhausting length of rapid firing.
A semi-automatic pistol with a mechanically locked breech short recoiled pistol, the USP's design was guided by the use of molded polymer frame and an ambition to inaugurate another 'HK pistol paradigm' as an addition to HK's rich history of pioneering firearm technologies.
HK pioneered the use of polymer materials in handgun design. All USPs have polymer frames reinforced with fiberglass and further stiffened with stainless steel inserts at areas subject to stress and friction. All major metal components on the USP are corrosion resistant. The external metallic surfaces are protected by HK's proprietary 'hostile environment' nitride finish. The USP is known to withstand even the most ridiculous of environmental conditions, for one boasting withstanding 5 megaton airbursts! All internal metal parts are coated with Dow Corning anti-corrosion chemical, reducing friction and wear over extended rapid fire sessions.
One of the most significant features of the USP is its mechanical recoil reduction system incorporated into the spring assembly system. The design primarily buffers the recoil effects on the pistol components, simultaneously reduces stress on the shooter's arm by 30%, while remaining insensitive to the ammunition type being used. The USP requires no adjustment or maintenance for the type of ammunition being used and allows the HK's trademark rapid, accurate and secure shooting experience.
The USP features an excellent trigger break. The DA/SA pull is 12 and 5 lbs respectively with an adjustable trigger stop for match grade variants. The oversized trigger guard extends utility for shooters using gloves.
The recoil system is coupled with HK's pioneered polygonal bore rifling profile and a one piece machined slide made from nitro carburized steel. This increases the muzzle velocity and barrel life. Furthermore, the locking surface on the barrel's locking tug has been tapered to create a forward slope, producing a camming action which assists in positive lock-up in presence of fouling and debris. These features enhance USP's reliability in high-dust environments, and allow easier cleaning.
Ergonomically, the HK USP is not suited for small handed shooters. It still features the traditional 3 dot sights with the rear sight adjustable for both windage and elevation. The USP Tactical variant features a threaded barrel and a higher front sight for use with a suppressor. The propriety universal mounting grooves at the front allow installation of accessories as well as rapid deployment of tactical devices in all variants. An ambidextrous magazine release coupled with the integrated lock-out safety device lets shooters an un-interrupted rapid fire sessions, both for sport or in time of need.