Diligence--Dan has it

At The Gun Zone, Daniel Watters posted a "5.56x45mm Timeline", which will probably lay to rest absolutely no intardnet/mall ninja/gun store commando arguments.

It goes back to 1882, to the very beginning of experimentation with Small Caliber, High Velocity (SCHV) ammunition.

From the Author's Note:

Alone, the saga of the .223 Remington and AR-15/M16 is a long tale of "NIH" (not invented here) skulduggery, panicked R&D fixes, all-out marketing efforts, old boys network flesh-pressing, inter-service rivalry, procurement end-runs, and Congressional witch-hunts. However, the saga becomes almost epic when you consider the related weapon systems (both competitors and accessories) along with the intellectual heirs of the SCHV and SALVO concepts, including the various micro-caliber rifle experiments and the current PDW craze. A careful reader will note that many ideas, solutions, and yes, even problems keep popping up again and again as the years pass.

Note this significant date:

1930,  January: Aberdeen Proving Ground's Robert H. Kent publishes "The Theory Of The Motion Of A Bullet About Its Center Of Gravity In Dense Media, With Applications To Bullet Design." It is shown that the size of a bullet's yaw in test medium is approximately independent of the striking velocity and the rifling twist. Giving examples for .30, .25, and .20 caliber projectiles, Kent notes that bullets with light noses are prone to early yaw, and suggests that lightweight, high velocity, small caliber bullets will cause more damage than heavier, slower, large caliber counterparts. Kent then argues the other benefits of SCHV rounds such as flat trajectories and low recoil.

Sound familiar?

h/t The Firearm Blog.