Howitzer Prep Marines prepare to fire an M777 howitzer during training at Marine Corps Air Ground Combat Center Twentynine Palms, Calif., Jan. 17, 2020. SHARE IMAGE: Download Image: Full Size (0.65 MB) Tags: Marine Corps, Training Photo By: Marine Corps Lance Cpl. Colton Brownlee VIRIN: 200117-M-ET234-1012C.JPG Photo Gallery