People think that the AR15 is a prom queen and can't take any abuse. Others think that it needs to be spotlessly clean to be reliable.
This is a demonstration of how much dirt the AR can take and still work. Unlike other demos, I don't just shovel dirt onto the rifle, I also put dirt into the rifle.
I also load the PMAG with dirt.
http://www.youtube.com/watch?v=dHwoZ6SS_pY
I would say the AR is able to handle more dirt than many people give it credit for.