im just an amateur, im not even old enough to own a gun yet, but im just curious, what is the difference between an AR15 and an M16?  are they the same gun?  all i know from watching the history channel is that the AR15 came first...that's about it...other than that it looks strikingly similar to an M4A1 Carbine

M16 usually refers to the military version of the rifle.  The AR-15 is the semi-auto civilian version.

There are 2 basic types of M16's.  The M16A1 was the one used in Vietnam.  It had the triangular barrel grip and could be shot on full automatic or semi auto.

The modern basic version today is the M16A2 with the tube-shaped front grip, and can fire in semi auto or 3-round burst only.

The M4A1 is just another variant of the M16, the only difference it has is a 14.5 inch barrel instead of the standard 20 incher and sometimes it comes in a flat top variant for mounting optics like scopes etc...

The M4 also has a collapsible stock (most of them). When you're old enough, you'll be the coolest kid on the block if you get one of those M4's. [;)]

I believe that the first Air Force contract select fire weapons were identified as AR15. Soon changed, or standardized, to the M16.

Actually, if I am not mistaken, the first Air Force contract for AR15s type-classified them as the GAU-2.

The first Army SF and adivsory units that tested them in Vietnam tested AR15s.

The Army first designated the rifles as M16s in 1965 when the decided to buy a bunch and equip units going to Vietnam with them.

No dumb questions (well, for the most part), only dumb answers. Welcome, you will learn a lot.

You can get technical about almost everything related to the AR/M16.  What raven said is a good basic description of the difference.

Hey we'll give this kid more info than he could ever want.

The AR15 is/was an Armalite-designed rifle that is selective fire in that it could shoot either full auto or semi-auto.  The company submitted it first to the Air Force for testing, then the Army got ahold of it.  Somewhere along the line, Colt bought the design from Armalite.  The Army liked the rifle and adopted it, calling it (for DoD purposes), the M16.

Colt marketed the AR15 in a semi-auto version for sale to civilians, because full auto weapons are either illegal or very hard to get due to government regulation, depending on where you live.  So today, generally, the AR15 has come to refer to a semi-auto rifle made by now one of several manufacturers that most of the people on this board can and do own.  M16 is the selective fire version of the same rifle (i.e., you can fire it semi or like a machinegun).  Very few of the people on this board own one of those, but all would like to . . . [;)]