The MCX Rattler is the most compact production MCX configuration, built around a 5.5-inch barrel optimized for .300 Blackout suppressed use. The folding stock collapses the overall length to under 17 inches — small enough to fit in a backpack or briefcase. Despite the ultra-short barrel, .300 BLK subsonic ammunition performs identically to longer barrels with a suppressor fitted. The Rattler is the quintessential suppressor host for close-quarters use. Type: Rifle Action: Semi-Automatic Caliber: .300 AAC Blackout Capacity: 30 Year introduced: 2016, USA Weight: 6 oz Overall length: 16.9" Status: Active Military use: Yes Intended use: military, law_enforcement, duty, suppressor_host