I picked up a new M&P 15 Sport II recently. Haven't fired it, yet. But that's going to be later this week. I've found quite a bit on youtube about how to clean and lube it. My question is regarding the BCG. I field stripped it to make sure I got the process down and knew what was what. However, the surfaces on the BCG are sort of sticky to the touch. Using some CLP and a cloth didn't improve things at all. Is this something that needs solvent, some oil? I'm new to the AR scene.