Marine grunts are applauding their new commandant's decision to arm the service's infantrymen with the M4 carbine in place of the iconic M16 rifle after years of close-quarters battles.

Sgt. Jeremy T. Wellenreiter, a primary marksmanship instructor with Weapons Training Battalion, fires an M-4 Carbine at Robotic Moving Targets at Marine Corps Base Quantico, Va., Sept. 24, 2013.