Caliber: .308 Winchester. Capacity: one supplied 20-round Brownells aluminum magazine. Compatible with metal DPMS/SR-25 magazines. Barrel: 20 in., 1:10 RH twist, 5/8-24 tpi muzzle threads, QPQ Nitride finish, 3-prong Dutch-style flash hider, .750-in. diameter at the gas block. Direct impingement. Upper/Lower Receivers: Machined from 7075 T6 aluminum billet. Stock: Type D, no trap door. Sights: Rear enclosed by the carry handle. A2-style horizontal thumbwheel adjusts elevation. Windage is changed by loosening a setscrew and drifting the rear peep. Standard AR-15-style front sight base. Weight: 8.6 lbs. Trigger: AR-15 style. Overall Length: 40.5 in. Features: Re-creation of Eugene Stoner’s original lightweight .308 caliber battle rifle, Armalite AR-10. Slab-sided lower with straight magazine well. Serrated takedown pins, selector lever, magazine release and bolt release. No forward assist and shell deflector. "Trigger"-style charging handle located under the carry handle. Carrier has flats and two stabilizing flanges at the rear found on early carriers, and the entire bolt/carrier group is chrome plated. Bolt machined from 9310 carbon steel and magnetic particle inspected (MPI). Functional heavy fluting on the barrel under the handguard. Brown furniture. Many components are compatible with modern DPMS/SR-25 parts or AR-15 parts. The BRN-10B is inspired by later export rifles and has a closed-prong, Portuguese-type flash hider, later-style black furniture, and a lightweight barrel. Weight: 7.8 lbs. Length: 40.75 in.