Description
Both the upper and lower receivers of the M4-SBR-L are machined from 7075-T6 aluminum billet and hardcoat anodized in a variety of colors. Since Franklin Armory uses CNC machines to carve out each receiver from a solid block of aluminum alloy, giving them a distinctly beefier look than usual, the company can also add custom features directly to the parts. The lower receiver has an integrated and e