Palmetto State Armory (PSA) PA-9 Gen4 4" 9mm Complete Upper Receiver w/ 6" M-Lok Rail
This PSA PA-9 Gen4 complete upper is a blowback 9mm Luger assembly built around a 4" heavy-profile, nitride-finished 4150V chrome moly barrel with a 1:10 twist and 1/2-28 muzzle threads. The slick-side billet 6061-T6 upper is paired with a 6" full Picatinny M-Lok free-float rail and a PSA fluted flash can.
This unit includes a Stern Defense MAG-AD9 Glock magazine conversion device, bolt carrier group, charging handle, buffer tube, and pistol brace. Flip-up front and rear sights are installed.