U.S. Marine Corps Lance Cpl. Nathaniel Prose with Weapons Company, 3rd Battalion, 7th Marine Regiment, Regimental Combat Team 6 prepares to conduct a battle sight zero for a 120mm mortar system on forward operating base Nolay, Sangin, Helmand province, Afghanistan, Feb. 29, 2012. Marines conducted the BZO to calibrate the accuracy of the weapon system.