I read an article in Shooting Times or Guns and Ammo where they did a torture test on six AR rifles from various makers. 3 gas guns and 3 piston guns. After dunking them in pond slime, oil, sand, concrete dust, and just about anything else they could think of guess who kept firing. 2 gas guns [including a RRA] and another make.
The piston guns didn't make it to the end of the test.
