The US Department of Defense also made an order for 500 VHS rifles. On May 12, 2009, Croatian Minister of Defence Branko Vukelić confirmed the positive conclusions of a series of torture tests and on May 15 officially signed a contract with HS Produkt for the acquisition of 1,000 rifles (both variants). As of 2015, the Croatian Army is using 7,000 VHS rifles. Design The VHS-D rifle is long, with a barrel. The whole rifle body is a monoblock construction made from high-impact polymer. Externally, it strongly resembles the French FAMAS rifle, but its operating mechanism and disassembly procedure are quite different. The VHS-K is a carbine variant with an overall length of and a barrel. Some characteristics of the rifle were not revealed to the public and provoked rumours during the development period. One involved a hypothesized venting system which recovered part of the gases generated from firing the weapon to cushion the bolt and dramatically buffer recoil. The production-stage VHS operated in a much more conventional manner, not utilizing this buffering system. According to the schematic filed at the European Patent Office (EPO) the misconception may have come from combining two different features: a forced air ventilation system similar to the one in Pecheneg machine gun and a mechanical buffer reducer, similar in conception to the one used in Ultimax 100, a weapon Croatia used in the Croatian War of Independence and retains in its reserve inventory. The same patent states that the VHS works neither through direct gas impingement nor through a short- or long-stroke piston, but through a 'tappet' type of closed gas system much like the FN SCAR. There may have also been confusion with another prototype which did not go into production. Confusion on the VHS's operating system was from several changes to the type of system used through its development. The first models used a Kalashnikov-style long-stroke piston, which was changed in 1999 to a lever delayed blowback system from the FAMAS. The next year, it was changed to a direct gas impingement system with a forced ventilation feature that formed a pneumatic cushion behind the bolt. The VHS was patented in that form in 2000 giving the impression of a "gas cushion" feature. That model was publicly known up to 2005. In 2004, the final and current operating system of the VHS was changed to a gas-operated, short-stroke piston system. When the