Sgt. Justin Parker (right), an infantryman with 1st

Sgt. Justin Parker (right), an infantryman with 1st Platoon, Charlie Company, 3rd Battalion, 15th Infantry Regiment, 2nd Infantry Brigade Combat Team, 3rd Infantry Division, explains how to load ammunition into an M249 squad automatic weapon to Pvt. Oscar Rios, an infantryman with Co. C During the “Best Rock” competition Sept.14, 2016 at Fort Stewart, Ga. The purpose of the “Best Rock” competition is to train and evaluate individuals in a competitive format as they demonstrate basic Soldier knowledge under stressful conditions. (U.S. Army photo by Spc. Corey Foreman / Released)