McChrystal said some assault weapons currently legal for civilian use should be limited to only the military.

"I spent a career carrying, typically either a M16 and later, a M4 carbine,” McChrystal said. "And an M4 carbine fires a .223 caliber round, which is 5.56 millimeters, at about 3,000 feet per second. When it hits a human body, the effects are devastating. It’s designed to do that. And that’s what our soldiers ought to carry.”

“I personally don’t think there’s any need for that kind of weaponry on the streets, and particularly around the schools in America," McChrystal continued. "I believe that we’ve got to take a serious look. I understand everybody’s desire to have whatever they want, but we've got to protect our children, we've got to protect our police and we've got to protect our population. And I think we've got to take a very mature look at that.”

McChrystal resigned his post in 2010 after controversial remarks he and his aides made surfaced in a Rolling Stone article. He was appearing on MSNBC to promote his new memoir, “My Share of the Task.”