Alpha Premium NiB V2 5.56 Bolt Carrier Group
Improved carrier geometry with M16 profile. NiB (Nickel Boron) plating reduces friction, adding corrosion resistance inside and out as well as wear resistance. Bolt machined from 9310 steel and MPI tested and marked. Carrier machined from 8620 steel. Shot peened precision ground diameters. Magnetic particle inspected and laser marked. Extractor machined from S7 tool steel Crane extractor O ring to boost extraction clamping force. Gas key: Machined from billet 4140 with grade fasteners and staked to mil spec. Chrome plated firing pin per mil spec.