Pwa Ar57 Lem 5.7x28mm Upper Lw/rail

The PWA AR57 LEM 5.7x28mm Upper with Lightweight Rail is a precision upper receiver assembly engineered for shooters building AR-platform systems around the 5.7x28mm cartridge. This upper transforms a standard AR lower into a compact, high-velocity platform suitable for tactical training, home defense, and precision work at intermediate ranges. The integrated rail system enables rapid accessory mounting for optics, lights, and other tactical hardware without requiring additional rail segments.

Chambered in 5.7x28mm, this cartridge delivers significantly reduced recoil and muzzle rise compared to traditional 5.56mm or 9mm platforms, enabling faster target reacquisition and controllability during rapid-fire sequences. The lightweight construction—4.81 lbs for the upper alone—minimizes fatigue during extended shooting sessions and improves handling in close-quarters scenarios. The 27.25-inch overall length reflects a full-size upper design, providing the velocity envelope this cartridge requires for consistent ballistic performance. The LEM designation indicates a lightweight profile upper without compromising structural integrity or rail rigidity.

This upper assembly suits operators and serious enthusiasts seeking a purpose-built 5.7x28mm rifle platform. The 5.7x28mm caliber appeals to shooters prioritizing shootability, low ammunition cost relative to larger rifle rounds, and subsonic-capable ammunition options. Compatibility with standard AR-15 lower receivers means shooters can repurpose existing lowers or build new platforms without acquiring entirely new firearm systems. The integrated rail design streamlines the build process and reduces part counts compared to traditional flat-top uppers requiring separate rail installation.