The LAR-PDS Pistol is Rock River's piston-driven short-barrel AR pistol designed for reliability in adverse conditions where direct-impingement carbon fouling becomes an operational problem. The piston operating system keeps the bolt carrier group cooler and cleaner than a comparable DI design, which matters in suppressed or high-round-count use. It was aimed squarely at law enforcement units who needed a compact 5.56 package that could be run hard. Type: Pistol Action: Semi-Automatic Caliber: 5.56 NATO Capacity: 30 Year introduced: 2009, USA Weight: 60.8 oz Overall length: 25.5" Status: Discontinued Intended use: Tactical, Law Enforcement, Home Defense