Upper Spring Cup LW Steel

The Upper Spring Cup LW Steel is a precision-engineered buffer tube component designed for AR-pattern rifles and tactical platforms requiring reliable spring retention and recoil management. Built by U-B Machine, this lightweight steel spring cup serves as the critical interface between your buffer spring and lower receiver assembly, making it essential for shooters who demand repeatable accuracy and consistent bolt carrier group cycling. Whether you're running a precision rifle, duty weapon, or competition build, this component ensures your action cycles predictably under sustained fire.

Constructed from hardened steel with a durable black powder coat finish, the Upper Spring Cup LW Steel accommodates 5 to 5.5-inch outside diameter buffer springs with a screw-on attachment design that eliminates the need for proprietary tools during installation or disassembly. The lightweight designation means this component reduces overall receiver extension weight without sacrificing durability or spring seat integrity, a critical advantage in carbine and precision rifle platforms where reducing reciprocating mass improves shot-to-shot consistency. The black powder coat protects against corrosion while maintaining a low-profile aesthetic compatible with modern tactical builds.

This upper spring cup is ideal for gunsmiths, armorer-level shooters, and tactical rifle builders who service or assemble their own platforms. Installation requires basic receiver extension removal and takes minutes with standard AR tools. For law enforcement duty weapons, military training rifles, and civilian tactical setups, this component delivers the reliability expected from U-B Machine's precision manufacturing. Ensure compatibility with your specific buffer spring diameter before purchase; most standard carbine springs in the 5 to 5.5-inch range will function reliably with this cup.