The MCX Rattler SBR with 5.5-inch barrel and folding stock — NFA-registered short-barreled rifle configuration of the most compact MCX. The definitive suppressed close-quarters SBR in the MCX lineup. Type: Rifle Action: Semi-Automatic Caliber: .300 AAC Blackout Capacity: 30 Year introduced: 2016, USA Weight: 5.9 oz Overall length: 16.9" Status: Active Military use: Yes Intended use: military, law_enforcement, suppressor_host