JP FMOS BCG's are how I get all my shit to function reliably in all conditions. Will work dirty and dry, suppressed or not in SBR's or whatever. I love these things. ONLY way to go. You want the slick black ones too, FWIW. The SS ones are probably fine but the slick shit they put on the others is unreal and how they work without lube. Not that they're meant to work without lube, just saying they will when most will start fucking up.