HK Heckler & Koch Mark 23. This is an original HK Mark 23 / SOCOM. 45 ACP barrel that was previously threaded, but the threaded muzzle portion was professionally removed by a gunsmith to meet California compliance requirements. It is now a non-threaded barrel and will NOT accept a thread protector, suppressor, or muzzle device. Used condition with normal signs of use. Please review all photos for exact condition, muzzle modification, finish wear, markings, and included item.