BCM Lower Group w/MK2RMS-M1T0 & BCMGUNFIGHTER Stock Mod-0-SOPMOD (Wide-body) - Flat Dark Earth - Utilizes the BCM MK2 Receiver Extension, MK2 buffer, and rifle M16 action spring. The MK2 receiver extension is approximately 3/4'' longer than the standard 6 position extension.Receivers Machined from Aluminum Forgings 7075-T6 Receivers Hardcoat Anodized per MIL-A-8625F, Type III, Class 2 MK2 buffer and rifle M16 action spring Fire Controls marked SAFE and SEMI
