APF firearms are made in America's heartland by craftsmen passionate about firearms, the outdoors, and supporting our nation's law enforcement agencies. Whether in the field or on the range, APF builds the caliber you want and offers an array of unique finishes and accessories to bring you the perfect upper receiver for your next rifle. FeaturesChrome-lined Shaw barrel for exceptional accuracy, durability, and easy cleaningPinned gas block optimized for short barrel rifle (SBR) reliabilityMagpul backup flip-up sights for fast target acquisitionShort barrel law enforcement / tactical configurationPrecision engineered for outstanding performance and reliability in harsh conditions