A few weeks ago I upgraded my stock BCG to the new Exo-coated FailZero BCG for my SHTF Bushmaster.
It'd been awhile since I shot the bushy, so the oil from the last cleaning was for the most part, evaporated.
I popped in the FZBCG and took it to the range to shoot some reloads..
The only failure I had was some kind of nasty double feed that ended up jamming a spent casing between the top of the BCG, charging handle and upper reciever. Very strange. But, I can't really attribute this to the BCG.
Other than that, the FailZero worked just fine with no lube after firing about 200 rounds.
I took it home and field stripped the AR and BCG. Everything looked just like it normally would.
The FZ BCG is pretty amazing. Despite not having any lube, the BCG still felt slippery. (sorry, no pics)