The USP is a semi-automatic pistol with a mechanically locked breech using the short recoil method of operation. This rather conventional lock-up system has a large rectangular lug over the barrels chamber that rides into and engages the ejection port cut-out in the slide. When a cartridge is fired, pressures generated by the ignited powder drive the cartridge casing back against the breech face on the slide, driving back both the barrel and slide as they remain locked together in the manner described above. After 3 mm (0.12 in) of unrestricted rearward travel, the projectile has left the barrel and gas pressures have dropped to a safe level. A shaped lug on the underside of the barrel chamber comes into contact with a hooked locking block at the end of the steel recoil spring guide rod, lowering the rear end of the barrel and stopping the barrel's rearward movement. The recoil spring assembly is held in place by the slide stop levers axis pin and a round cut-out at the front of the slide. For enhanced reliability in high-dust environments, the locking surface on the front top of the barrels locking lug is tapered with a forward slope. This tapered surface produces a camming action which assists in positive lock-up in the presence of heavy fouling and debris.
Magazine: 18+1 rounds. Compatible w/ Elite Force USP CO2 Magazines Gas Type:CO2 Firing Mode: Semi Automatic, Safety System: Blowback Hopup: Yes, Adjustable Package Includes: Gun, Magazine, and Manual Manufacturer: Umarex / H&K