Today we had the opportunity to speak with L. James "Jim" Sullivan, one of the original designers of the AR-15 rifle. He started working as a draftsman for Eugene Stoner at Armalite, and wound up being largely responsible for converting the AR-10 down to .223 caliber. His later work would include the Ultimax LMG, Ruger Mini-14, and many other firearms.
Recently, Jim has gone back to the AR-15, designing 60- and 100-round quad-stack magazines for Surefire. He has also designed a number of modifications to the rifle to improve its controllability and ability to handle a continuous high rate of fire. The modifications include:
Heavier bolt carrier
Anti-bounce floating weight in the carrier
Heavier, radiated gas tube
Adjustable gas port
Open-bolt full auto FCG (closed-bolt when in semiauto)
Hopefully these modifications will be brought to market by Surefire, but if not they will become available to any other manufacturer interested in licensing them from Mr. Sullivan.