"Wet" is not dripping-at least when I was introduced to the AR system. And, the flour like sand of Iraq just might justify that, don't know, wasn't there. "Dripping" generally ends up depositing significant lube in the receiver extension, where it doesn't belong and can compromise normal operation.

Caj, ever hear of the SWAG? Scientific WAG-source has specific knowledge that may/may not apply to the situation.

With that in mind, in a post above, the broken cam pins might well have happened during unlocking of the previous round, trapping the firing pin in a forward position and enabling a slam fire. In the half dozen or so events I've seen, the cam pin was intact. Again, a situation where someone would need to attempt to duplicate the event.