Franklin Armory BFSIII M4 Built Lower Receiver Features The Franklin Armory BFSIII M4 Built Lower Receiver starts with a forged 7075-T6 aluminum receiver the same material standard used across mil-spec AR builds chosen for its strength to weight ratio and resistance to wear over heavy use. A specialized tension screw is built into the design to eliminate the upper and lower receiver play that is common on many AR-pattern rifles tightening the overall fit and improving perceived build quality. The receiver is finished in a hardcoat Type III anodized black coating that resists corrosion and abrasion keeping the lower protected through repeated range sessions and field use. This combination gives builders a reinforced precisely fitted foundation to build on without sourcing or fitting a receiver separately. Equipped from the factory with the Franklin Armory Binary Firing System AR-Essential trigger this lower lets a shooter fire one round on trigger pull and a second round on trigger release a significant upgrade over a standard single stage trigger group. The A2 pistol grip and reinforced six position collapsible M4 stock provide familiar ergonomics and quick length of pull adjustment while multiple rear sling mounts and an angled heel aid faster transitions between shooting positions. A 30 round magazine manufactured from stainless steel with a Marlube finish and anti-tilt follower ships with the lower with 10/20 or 10/30 configurations available for restricted states. For builders who want a binary trigger ready lower without separately sourcing and installing a trigger group the Franklin Armory BFSIII M4 Built Lower Receiver is available for sale at GrabAGun. Franklin Armory BFSIII M4 Built Lower Receiver Specifications Manufacturer: Franklin Armory Model: BFSIII M4 Built Lower Receiver Type: Accessory-Lowers Action: Semi-Auto Caliber: Multi-Cal Receiver Material: Forged 7075-T6 Aluminum Finish: Hardcoat Anodized Color: Black Grip: A2 Pistol Grip Stock: M4 Collapsible Stock Trigger: BFSIII AR-Essential Binary Trigger Magazine: 30 Round Steel Magazine Capacity: 30+1 Safety: BFSIII Binary Safety Selector Weight: 3.3 lbs Available At: GrabAGun