A Republic of Korea Marine zeroes out his weapon before teaching U.S. Marines how to fire it Feb. 5 during Korean Marine Exchange Program 15-3 at Gimpo, Republic of Korea. Zeroing the weapon, combined with the proper application of the fundamentals of marksmanship, allows for the rifle optics to align with the targets downrange. U.S. Marines also learned different characteristics of the weapon. The U.S. Marines are reconnaissance men with Alpha Company, 3rd Reconnaissance Battalion, 3rd Marine Division, III Marine Expeditionary Force. The ROK Marines are with 2nd Battalion, 2nd Marine Division.