SIG Sauer introduced its brand new MPX submachine gun at the 2013 SHOT Show in Las Vegas. Functioning similarly to an AR, this submachine gun features ambidextrous mag releases and controls, as well as fully locked breech and bolt. In addition, the MPX's caliber can be easily swapped with few tools. The MPX comes in several variants, including a ranging from the short MPX-K to a 16-inch version, and are available with either a telescoping stock or a folding stock. The MPX also comes with 30-, 20- and 10-round magazines. Check out the video straight from SHOT Show.