The VK-1 rifle uses a patented low-profile piston system design featuring optimum gas port sizing and an advanced piston assembly. This features a unique cup and spigot design that improves the gas seal and overall efficiency of the gas system. The VK-1 also includes a staged gas bleed system that allows the rifle to operate consistently, either suppressed or unsuppressed, with varying types of factory ammo. The reimagined VK-1 Short Stroke Piston System includes a fully-supported one-piece op rod and removable gas block which matches the footprint and weight of a standard DI AR-15 while providing the benefits of a piston driven system. *This rifle includes a Gen 3 Compmag to meet California compliance* Patented Billet Ambi Controls - Fully ambidextrous, including a patented billet machined magazine release and bolt catch. Heat-treated billet construction ensures these components will perform for a lifetime of service even in the most hostile conditions. Heavy Duty Buffer Retainer - Patented design with a precisely angled strike face that corresponds to the vertical plane of the buffer assembly giving a greater area of surface contact. The last retaining pin you will ever need. Bolt Carrier Group - Precision machined one-piece patented bolt carrier with a true 22.5 degree long advanced cam path, finished in thin, dense chrome. The patented long enhanced cam path provides for consistent lock up, shot after shot. This results in increased reliability, minimal muzzle rise, and reduced recoil.