I have a 2011 with the plastic thread protector. I checked the gas ports and I actually have three but it still won't cycle low brass ammo on the #2 setting. It will get really close to ejecting the shell then jams. On setting one it won't even push the carrier back far enough to jam. It just slides the empty back into the chamber. It will cycle high brass, buck and slugs just fine though. I am curious about swapping the puck and plug though. Has anyone done this and had their gun start cycling low brass without other modifications? What other mods would you guys recommend to be able to cycle