The Cav Arms guys did an extreme dust test on an AR-15. Turns out AR-15 cannot handle being buried in sand and then run over by a Jeep … who knew? Apart from the “Jeep test”, it did really well.
They also tested an AK derivative, a 5.56mm SAR-3, which did not do as well. It seems odd that the trigger group would fail to function. I have posted videos on the blog showing AKs working under worse conditions.