U.S. Marines with 3rd Battalion, 6th Marine Regiment, 2nd Marine Division, test the power of snow during Mountain Training Exercise (MTX) 2-20 at Marine Corps Mountain Warfare Training Center, Bridgeport, Calif., Feb. 6, 2020. The Marines opened fire on blocks of Snowcrete, a mixture of snow and water frozen in a cardboard box, to test the effectiveness of its stopping power on a bullet. (U.S. Marine Corps video)