The MK22 Mod 0 can be changed to fire three different calibers.. U.S. Marine Corps Systems Command has achieved Fully Operational Capability (FOC) for the MRAD MK 22 Mod 0 Advanced Sniper Rifle (ASR) a year ahead of schedule. The MK 22 represents the culmination of Barrett’s dedication to innovation and collaboration with the Department of Defense. Originally developed through a Special Operations Command contract, the MK 22 transitioned to the Marine Corps via the “Special Operations Forces to service” process, with contracting led by the U.S. Army. The seamless interservice cooperation enabled the Marine Corps to achieve FOC a...