Quote Originally Posted by The Storyteller View Post
I remember in the Marines dropping by a gun store to humor a friend and was surprised to see an AR-15. It looked exactly like an M-16. I broke it down and the only difference I could find was the ability to switch back and forth to automatic fire, although this was very superficial.
You know why the AR-15 and the M-16 look so similar? Because Colt based it's initial M-16 design on the former, turning a semi-automatic rifle into a fully automatic assault weapon.

I've noticed many folks think it's the other way around.