Jams do happen due to dirt and mud getting into the rifle. My point is that AR-style rifles can still perform even if they become mudballs thanks to their sealing nature. Like what @TerraN_EmpirE said, the concept of AR15's easily intaking small amount of mud and getting jammed has been proven to be false. In the examples I mentioned, the AR-style rifles both went through extremely austere environments, ie muddy terrain, and they both did well.I'm talking incredible build-up of crap between that barrel and fancy hangrip and suppressor.... all these artifice are insane dirt trap. Nowhere I have talked about jam... These gun will become mudballs, probably good for enhancing camo.