Did Eugene Stoner make a mistake. Did he fail to see the inherent down side of his gas operating system when designing the AR-10 rifle?
I've been hanging out with a bunch of high capacity, high speed, low drag three gun shooters lately. I work on some of their guns and try to keep them running right. We shoot the AR platform rifles of various makes, usually in the 5.56 caliber, and shoot about 1000 rounds per week, per gun. Some of the brands are Larue, Rock River, LWRC, Armalite, DPMS, BCM, etc. Many are custom made with various aftermarket accessories. Some are good, some are not so good. I have converted a few of these to the piston system and the owners were happy wiht the results. One particular off the shelf model that stands out and is envied by many are the LWRC piston driven guns. Short stroke piston operated guns do not dump hat gas and propellant residue into the critical moving parts as do the Stoner system guns. This seems to be a cooler and less trouble prone system. The Stoner system, often called a direct gas impingement system, though I believe it is an internal piston system, brings with it an unavoidable side effect of hot high pressure gas into the internals of the receiver. It is obvious some Stoner system guns are better quality than others but those piston guns are cooler and require much less cleaning to stay in the fight. Several hundred rounds won't even burn the oil off the bolt on these cool piston guns. In the same number of rounds through a Stoner system gun will usually carbon the rings together and burn all lube off the bolt and carrier.
I was wondering what guns are used around the shooting circuit and what folks think of the piston guns. I've heard it said that the piston system is a good fix to a non existent problem. Well I disagree with that and always have. I considered this internal gas system to be troublesome four decades back and other than closer tolerances and higher quality of manufacture they are the same guns. I'm moving ahead and with progress and grabbing a piston driven gun whenever I can. I have a LWRC, M6 SL, 6#, 14.7" rifle that has really shown up as a very high quality built gun. A great shooter and care and upkeep are minimal.