Chambered in 5.7x28, mounts to a regular AR lower, and takes PS90 mags. Runs great, barely again recoil, and is especially fun to shoot suppressed. Upper comes complete with bolt & buffer. Minor wear from use, but under 100 rounds ran through it. Interested in trading for a pistol in 45 ACP. Interested in other trades as well just let me know what you have. Located in Argyle, TX. If interested text 940eight0eight4572