[Durus]

No I didn't concede your point. An AR doesn't need "constant" cleaning. Does it need to be cleaned more than a piston? Yes. Even a piston platform needs to be cleaned. There is no such thing as a perfect rifle and all platforms have strengths and weakness. A rifle has to do more than go BANG every time you pull the trigger. It has to be capable of the accuracy required to hit what you are aiming at. The biggest weakness of a piston platform is accuracy. The biggest weakness to the m4 is the caliber. The second biggest weakness is also one of it greatest strengths. Because it's a gas impingement system, powder residue is deposited in the chamber, but because it is a GI system it is also more accurate than a piston. Chrome plating the bolt mitigates the weakness while preserving the strength. Putting something other than 5.56 in the stoner platform removes its biggest weakness.

[donozark]

Doubt if we can ever come up with a one size fits all weapon. Russia faced similar problem with the AK-47 vs. the AK-74. Dr. Kalashnikov did not want the caliber of "his AK" changed in any way. But of course he takes orders like all do. The AK-74 was designed to increase the range of lethality for the Russian soldier. It did so in 'Stan and became known as "the poison bullet" by the Muj.

However, in the Battle of Grozny 1 and later 2, the Russians noted penetration problems with the smaller round in a urban setting. Ultimately Grozny became known as the "most destroyed city in the world." This as a result of fuel-air bombs and arty. Most Russian units went back to the Ak-47.

I agree transitioning from one platform to another (especially in the middle of a war) is probably not the best thing to do.

[Gaffer]

Even a piston platform needs to be cleaned.

True, but the piston's location isn't usually in the chamber area as is the gas port on the AR platform. In the Garand it is far forward near the muzzle and in the M-1 Carbine it is below and forward of the chamber, isolated. Allowing gas exhaust and particles in the chamber area (behind the throat) to me is a bad idea.....