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USP
One of the remarkable features of the USP is the wide variety of the trigger styles available, which may be quickly swapped. There are nine commercially available modifications (called "variants" by HK).
By using a modular approach to the internal components, the control functions of the USP can be switched from the left to the right side of the pistol for left handed shooters. The USP can also be converted from one type of trigger/firing mode to another. This includes combination of double-action and single-action (DA/SA) modes and double-action only (DAO) modes.
In addition to a wide selection of trigger/firing modes, the USP has an ambidextrous magazine release lever that is shielded by the trigger guard from inadvertent actuation. The rear of the USP grip is stepped, and combines well with the tapered magazine, making magazine changes faster due to lack of user-assisted guiding. Finger recesses in the grip frame also aid in magazine removal. On 9 mm and .40 caliber USPs, magazines are constructed of polymer reinforced with stainless steel. Magazines on the USP .45 are all-metal. All USP magazines will drop free of the pistol frame when the magazine release is depressed. Also, the USP does not have a magazine lockout feature â€" it is possible to fire a chambered round even with the magazine removed. An extended slide release lever is positioned to allow easy operation without changing the grip of the shooting hand.
Variant 1 and 2 (double action/single action, decocking and safety lever)
Variants 1 (lever on left)and 2 (lever on right) allow the user to carry the pistol in a single-action mode (cocked and locked) with the manual safety engaged. This same pistol, without modification, can be carried in double-action mode, with or without the manual safety engaged, and with the benefit of a decock lever.
Variants 3 and 4 (double action/single action, decocking lever, but no safety)
Variants 3 (lever on left) and 4 (lever on right) provide the user with a frame-mounted decocking lever that does not have the "safe" position. This combination only allows the hammer to be lowered from SA position to DA position. It does not provide the "safe" position to prevent the pistol from firing when the trigger is pulled.
Variants 5 and 6 (double action only, with safety lever)
For the double action only user, variants 5 (lever on left), 6 (lever on right), and of the USP operate as double action only pistols with a bobbed hammer always returning to the DA position (forward) after each shot is fired. To fire each shot, the trigger must be pulled through the smooth DA trigger pull. Variants 5 and 6 have a manual safety lever.
Variants 7 (double action only, no control lever)
No control lever is provided on variant 7.
Variants 8 and 9 (double action/single action, safety lever, but no decocking)
Variants 8 (lever on left) and 9 (lever on right) allow the shooter to carry the pistol in a single-action mode (cocked and locked) with the manual safety engaged. This same pistol, without modification, can be carried in double-action mode (hammer down), with or without the manual safety engaged. The single action mode offers a second strike/double action capability in case of a misfire. The control lever has no decocking function on variants 8 and 9.
USP
One of the remarkable features of the USP is the wide variety of the trigger styles available, which may be quickly swapped. There are nine commercially available modifications (called "variants" by HK).
By using a modular approach to the internal components, the control functions of the USP can be switched from the left to the right side of the pistol for left handed shooters. The USP can also be converted from one type of trigger/firing mode to another. This includes combination of double-action and single-action (DA/SA) modes and double-action only (DAO) modes.
In addition to a wide selection of trigger/firing modes, the USP has an ambidextrous magazine release lever that is shielded by the trigger guard from inadvertent actuation. The rear of the USP grip is stepped, and combines well with the tapered magazine, making magazine changes faster due to lack of user-assisted guiding. Finger recesses in the grip frame also aid in magazine removal. On 9 mm and .40 caliber USPs, magazines are constructed of polymer reinforced with stainless steel. Magazines on the USP .45 are all-metal. All USP magazines will drop free of the pistol frame when the magazine release is depressed. Also, the USP does not have a magazine lockout feature â€" it is possible to fire a chambered round even with the magazine removed. An extended slide release lever is positioned to allow easy operation without changing the grip of the shooting hand.
Variant 1 and 2 (double action/single action, decocking and safety lever)
Variants 1 (lever on left)and 2 (lever on right) allow the user to carry the pistol in a single-action mode (cocked and locked) with the manual safety engaged. This same pistol, without modification, can be carried in double-action mode, with or without the manual safety engaged, and with the benefit of a decock lever.
Variants 3 and 4 (double action/single action, decocking lever, but no safety)
Variants 3 (lever on left) and 4 (lever on right) provide the user with a frame-mounted decocking lever that does not have the "safe" position. This combination only allows the hammer to be lowered from SA position to DA position. It does not provide the "safe" position to prevent the pistol from firing when the trigger is pulled.
Variants 5 and 6 (double action only, with safety lever)
For the double action only user, variants 5 (lever on left), 6 (lever on right), and of the USP operate as double action only pistols with a bobbed hammer always returning to the DA position (forward) after each shot is fired. To fire each shot, the trigger must be pulled through the smooth DA trigger pull. Variants 5 and 6 have a manual safety lever.
Variants 7 (double action only, no control lever)
No control lever is provided on variant 7.
Variants 8 and 9 (double action/single action, safety lever, but no decocking)
Variants 8 (lever on left) and 9 (lever on right) allow the shooter to carry the pistol in a single-action mode (cocked and locked) with the manual safety engaged. This same pistol, without modification, can be carried in double-action mode (hammer down), with or without the manual safety engaged. The single action mode offers a second strike/double action capability in case of a misfire. The control lever has no decocking function on variants 8 and 9.
