An AR15 80 percent lower receiver is a partially machined lower receiver for AR-15 rifles, not yet classified as a firearm. It requires additional milling to become functional. Once completed, it works with AR-15 upper receivers, lower parts kits, buffer tubes, stocks, magazines, and other standard AR-15 components. The AR15 80 percent lower receiver is ideal for DIY builders seeking customization and compatibility for hunting, target shooting, or tactical AR-15 builds.