ArmaLite was asked to develop a smaller version of the AR-10 (rifle that was developed to replace the M14)in 1956. This new rifle was called the AR-15.
Production of the AR-15 rifle was licensed to to Colt Manufacturing Company in 1959.
AR-15 was gas operated, air cooled, magazine fed, selectable for full and automatic fire.
The AR-15 was re-designated by the US Army as the M16 rifle, and in 1967 the Army adopted it as the standard infantry weapon
Later in 1967 the M16A1 was adopted by the US Army. It featured a positive forward assist to help close the bolt when dirty, chromium plated chamber and bore to resist corrosion and an improved gas system with a new bolt buffer designed to reduce the rate of fire on full automatic.
The M16A2 replaced the M16A1 in U.S. Army service in 1983. It is essentially an improved M16A1. Major changes include: a switch from full automatic to 3-round burst capability; a heavier barrel; improved sights; new, stronger plastic butt stock, hand guard, and pistol grip.
The M16A2E4 rifle is a standard M16A2 Rifle modified by changing the upper receiver to a flat-top upper receiver with a detachable carrying handle (which then is lost or thrown away, causing commanders to pull their hair out at change of command inventories).
The M16A3, which replace the M16A2 in 1994, is basically an M16A2 with full-automatic capability and optional M4A1-style Rail Interface System (RIS).
The M16A4 is identical to the M16A3, but can fire single shots or 3-round bursts (no full auto).
In 1994 the M4 and one sub variation was adopted. The United States Carbine, Caliber 5.56mm NATO, M4 uses the new 14.5” barrel and collapsible butt stock, but was first issued with the standard M16A2 upper receiver and sights to streamline production, though it now is made with the new modular upper receiver.. With a detachable carrying handle (which then is lost or thrown away, causing commanders to pull their hair out at change of command inventories) .
Sorry if this came out as a diatribe

, not how it is intended… LOL.. 24 years of carrying the thing,

reciting “The M16 /M4/ 5.56mm Carbine is a lightweight, gas operated, air cooled, magazine fed, selective rate, shoulder fired individual weapon” at countless boards though the years and hearing hundreds if not thousands of Soldiers over the years learn and recite the same…. Makes this stuff ingrained and just flow forth without much thought.
I will now go back to my corner .. besides it's time for PT..

MONDAY = Combatives...
ScottDLS wrote:AndyC wrote:TLE2 wrote:Just for my own edification: Why do you call an AR-15 an "M4-gery"?
It's a commonly-accepted nickname by enthusiasts for the civilian lookalikes of the military M4.
Not to mention the "AR-15" designation has been completely misused for over 30 years now, with everyone from Colt to Joe-Bob's Machine Shop coming out with an "AR-15". If you mean the original select fire Armalite rifle, it's been the common vernacular since the early '80's to so specify... i.e.
Armalite AR-15. After the design was adopted by the Army (although I've been told the Air Force might have been first), Colt got the bulk of the manufacturing and military designated it the M-16.
I think M4-gery is a creative description of the semi-auto "look alikes" of the M4. I think most people use "AR-15" when referring the the semi clones of the full size M-16's.