[oniwagamaru]

in your last picture, that tab still has to go in the front cap. I think the reason why it still has play is because of the last sentence you wrote. I dont think they replicated the RAS properly like the real one from KAC. I think your other M4 is stable because of the prong like nature of that bar which clings to the barrel nut once you tighten the screw. without that, the bar is pretty much useless.