I don't know Delphi. I've been an Instructor and maintainer of M-16's for almost 30 years. Our training rifles had hundreds of thousands of rounds through them, to the point that we'd some times see Double Fires from the sear surfaces being badly worn. I never replaced a gas ring unless it was badly worn. When stationed at Lowery AFB, we ran 4 classes a week and up to 40 students per class. I was there for 4 years and in all that time, I don't think we ever had to replace more than 3 or 4 sets of gas rings. I never replaced the extractor unless it was missing or broken, and I never saw one break. We did replace the extractor Springs from time to time.

As for magazines, the double feed is caused by the lips of the mag being worn or bent to the point that it allows the rounds to set too high in the mag. When the bolt goes forward, it can then try to strip 2 rounds from the mag. When we made the move to 30 round mags, we'd regularly fill them to max without any problems. Where filling them can cause problems is if they are stored for extended periods full. Our Security folks carry full mags at all times, but as armorers, we'd change out the mags about every month or so. That way the spring is not always compressed, and can relax. Never had a problem with any of them.

What you may have run into was that you were probably using a brand new rifle that still had some burrs and rough edges that caused problems. You just have to make it through the breakin time for your rifle. One huge and really major problem with the AR is that stupid massive cut in the underside of the bolt carrier combined with the equally stupid notch in the top of the hammer. It was said that these cuts were made to prevent conversion but the only thing they really do is cause the weapon to self-destruct, and jam like a SOB. There are always rough edges between these two parts and it's been my experience that it is the major reason for jamming AR-15's. You just don't see this with the M-16, because the surface of the Bolt Carrier that re-cocks the Hammer is flat and smooth as a babies butt, and the top of the hammer is rounded and equally smooth.

When at Lowery in '82, a representitive of the CBI came to visit. They'd just picked up a bunch of AR's for their officers and were having major jamming problems. I told him the same thing. I said if you'd just swich out the hammer and bolt carrier for ones from an M-16, those problems would go away. He said that would make it full auto, so I sat him down and explained how FA works. I don't know for sure if they ever made the change or not.

As far as graphite in the mags and on the ammo, I don't suppose that could hurt, so long as you don't get too much of a build up. I know that you should never leave oil in the chamber, nor should you oil your ammo as that can cause an increase in the chamber pressure and possibly lead to one or more of the following:
1. Ruptured cartridge
2. Excessive blow back
3. Chamber failure, i.e. it blows up in your face.

Finally, I do agree that you should always keep your weapon clean, however, in a very sandy environment, the oil can attract the sand and dirt kicked up by fireing and cause a nasty sludge to build up that can lead to any number of malfunctions.

The main thing to do though, to prevent malfunctions, is get out and shoot. Wear down the rough edges and get that puppy used to functioning. If you have one that is particularly rough, you can apply some toothpaste to the friction surfaces and cycle the action a few hundred times. That will polish those surfaces nice and smooth.

That's my 2 cents. Ok, maybe a quarter, inflation you know.