Aero Precision M4E1 in .223 Wylde chamber — the hybrid chamber accepting both .223 Rem and 5.56 NATO while providing superior accuracy over standard 5.56 chambers. Particularly popular as a competition build base. Type: Rifle Action: Semi-Automatic Caliber: .223 Wylde Capacity: 30 Year introduced: 2018, USA Weight: 96 oz Overall length: 32.5" Status: Active Intended use: Competition, Service, Home Defense