Zenith Firearms ZF-56, Semi-automatic Pistol, 556NATO, 14.5 Barrel, Threaded 1/2x28, 3 Prong Flash Hider, Matte Finish, Black, Polymer Grip, Manual Safety, Free Float M-LOK Handguard, 30 Rounds, 3 Magazines ZF56000145 The ZF-56 14.5" is a semi-auto pistol with a roller-delayed blowback operating system. This pistol is chambered in 5.56 and comes with a full length Picatinny rail, & a cold hammer-forged barrel. The American Made ZF-56 also features a last round bolt hold open system. This firearm features a buffer tube compatible end cap.