An AR-15 stock is the buttstock component for AR-15 rifles, providing shoulder support, stability, and comfort while shooting. Available in fixed or adjustable (collapsible) styles, the AR-15 stock works with AR-15 lower receivers, buffer tubes (carbine or rifle length), buffer assemblies, end plates, and castle nuts. It’s essential for customizing fit and handling, making it ideal for hunting, target shooting, tactical, and competition AR-15 builds.