Grand Power K100 The K100 is a 9 mm semi - automatic pistol designed and built by Grand Power s . r . o . in Banská Bystrica , Slovakia . Development . The K100 was developed by Jaroslav Kuracina , a former weapons officer in the Slovak Army . Kuracina sketched drawings of the K100 as early as 1992 , but manufacturing activities were highly restricted during the early post - Communist era . Kuracina would be forced to wait until 1996 to continue development of his design . In 2007 Grand Power announced a deal to produce 100 , 000 units for the U . S . market in partnership with Texas - based handgun manufacturer STI International Inc . The first pistols were exported in 2008 . They were K100 Mk6 pistols under the commercial name GP 6 . 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 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 .