Aero Precision M4E1 Competition with 20-inch barrel and enhanced competition furniture. Full-length Picatinny top rail. Built for 3-Gun and precision AR competition. Type: Rifle Action: Semi-Auto Caliber: 5.56 NATO Capacity: 30 Year introduced: 2019, USA Weight: 64 oz Overall length: 37.5" Status: Active Intended use: Competition, Precision, Long-Range