Lance Cpl. Johnathan Eckart assembles an M2 .50 caliber machine gun. U.S. Marine Corps Lance Cpl. Johnathan Eckart, of 3rd Battalion, 11th Marines Headquarters Battery, assembles an M2 .50 caliber machine gun during a crew serve weapons class at Marine Corps Air Ground Combat Center, Twentynine Palms, Calif., on March 3, 2009. SHARE IMAGE: Download Image: Full Size (0.04 MB) Photo By: VIRIN: 263795-W-ONP06-417.jpg Photo Gallery