Editor’s Note: Many AR-9s are pushed to market as cheaper alternatives to more expensive pistol-caliber carbines, but not the Angstadt Arms UDP-9. Despite still being a direct-blowback firearm, these feature a much higher build quality with some excellent features like a flared magwell and last-round bolt hold open. If you are looking for a reliable and accurate PCC that has AR-like controls and uses common Glock magazines, this is a great option.