U.S. Army Lt. Col. Nathan Watanabe, a history professor at the Air Force Academy, shows an M1898 Krag-Jorgensen rifle to a class of Academy cadets April 19, 2015, at Fort Carson, Colo. The cadets took part in an Academy Historical Weapons Shoot and handled and fired 27 historic military firearms, including the 1766 Charleville Musket, the 5.56mm M16A4 Rifle and the M4 Carbine, to better understand the small arms used by the U.S. military throughout its history. (U.S. Air Force photo/Lt. Col. Don Langley)