Marines with Golf Battery, 2nd Battalion, 10th Marine Regiment, 2nd Marine Division, employ the M-777 lightweight 155 mm howitzer during a competition for the title of Top Gun as part of Rolling Thunder held at Fort Bragg, N.C., May 7, 2014. Rolling Thunder is a biannual field operation in which Marines learn to be more proficient at effectively employing their respective weapons systems. - Marines with Golf Battery, 2nd Battalion, 10th Marine Regiment, 2nd Marine Division, employ the M-777 lightweight 155 mm howitzer during a competition for the title of Top Gun as part of Rolling Thunder held at Fort Bragg, N.C., May 7, 2014. Rolling Thunder is a biannual field operation in which Marines learn to be more proficient at effectively employing their respective weapons systems.