“I spent a career carrying typically either an M16 or an M4 Carbine. An M4 Carbine fires a .223 caliber round, which is 5.56 mm at about 3000 feet per second.”

American general

Stanley A. McChrystal is a retired United States Army general who served in the early 21st century. He is best known for leading Joint Special Operations Command from 2003 to 2008, and for later commanding United States and NATO forces in Afghanistan. During his time at JSOC, the command was credited with the killing of Abu Musab al-Zarqawi, the leader of al-Qaeda in Iraq. He later served as Director of the Joint Staff from August 2008 to June 2009, then as Commander of the International Security Assistance Force and United States Forces, Afghanistan, from 15 June 2009 to 23 June 2010. He was also criticized for his alleged role in the Pat Tillman friendly fire cover-up, and was said to be willing to say aloud what other senior officers only thought.