Grand Power K100 - Design Details

Design Details

The K100 uses a rare locking system, similar in some ways to the Beretta Cougar, Px4 Storm, and Brügger & Thomet MP9 which employs a rotating barrel lock, which in the K100's case is cammed by a cross pin. When the pistol is fired the barrel and slide move backward together for about 3/8 of an inch while the barrel is cammed clockwise (with respect to the shooter) by a flat, twisting, helical "cut" in the barrel extension. Once the barrel and slide have moved back to the point where the barrel has twisted about 45°, the slide is free to continue traveling back while the barrel's travel is arrested by its interface to the frame via the barrel extension's square shoulders. On the K100, the Beretta's barrel extension cam cut, and transfer block's cam tooth, are replaced by a curled, twisting cut in the barrel extension, and a round, frame-embedded cross-pin respectively. As such, there is no transfer block (locking block) per se, and the barrel extension directly interfaces with the frame via the replaceable cross-pin. The design allows a low bore axis relative to the shooter's hand and avoids the use of the transfer/locking block typically found in rotating barrel pistols.

Both of the Berettas, and the K100, have the archetypal square shouldered lock protruding from the otherwise round barrel, easily visible at the ejection port with the slide fully forward. This square shoulder is rotated in behind a solid column of steel running the length of the slide forward of the ejection port, and on the left side out of view, when the slide and barrel are fully forward in battery. This locks the slide forward in battery. Given that the MP9 uses the same basic locking mechanism, and has a cyclical rate of fire of 900 rounds/min, the rotating barrel lock has shown itself to be capable of very fast lock times.

The thick walled barrel and other metal parts are treated by Tenifer QPQ technology. This hardens the metal components and increases resistance to corrosion.

The standard K100 has a barrel length of 108 mm (4.3 in) and operates in both single and double action mode. There is no decocking lever, the hammer must be manually decocked for carry in double action mode with a chambered round. The safety can be applied with the hammer cocked, but can not be applied with the hammer in the forward position. The safety does not lock the slide.

The ergonomically shaped polymer grip frame houses a steel receiver which provides the rails the slide travels on as well as hardpoints required for the trigger mechanism. The slide spring guide, safety, trigger, and trigger guard are polymer.

The pistol's toothy surface, and grooved grips, provide good grip even with wet hands. The K100 also features ambidextrous controls, supporting both left and right-handed users. When field stripping, the forward part of the trigger guard unlatches from the gripframe and is flexed downward out of the frame. With the forward part of the trigger guard flexed downward, the slide moves farther to the rear than normal and can be pulled to the extreme rear and then lifted up and off the frame. The field strip is roughly similar to the Walther PPK/PPKS fieldstrip except that the triggerguard is not hinged on the K100, its polymer construction allows it to flex downward.