Regular Cerakote will not effectively stick to the chrome plating on your BCG and is not intended for moving parts.
NIC also makes another Creakote product called Micro Slick that some use in that application, Next Gen Arms, but again your chrome plated BCG will not coat very well as the reason for the plating is to keep crap from sticking.
Take the advice to get the melonited gas tube. The area inside the handguard is going to be shaded, so the black melonite will hardly show and it’s going to last.
Is there any functional reason for some sources selling a melonited gas tube, or is done just because they can? Secondly are the melonited gas tubes still made from stainless? If so from what I understand meloniting stainless can reduce it’s corrosion resistance.
I’m guessing it’s just to make the stainless black. The corrosion issue is something we might ask the makers. I see things on the web that imply that there are different methods of applying meloniting, one of which is not suitable for stainless because of corrosion. So for stainless, they skip the last “Q” in the usual “QPQ” process.
I’m more impressed by experience than theory. My own experience with it has been less than a year, so I can’t speak for my tube’s endurance. This fellow, though, used a stainless barrel for testing and the melonite seems to have done well.
http://68forums.com/forums/showthread.php?26592-melonite
I was refering only to the use of melonite on a gas tube.
On barrels, when used in conjunction with an appropriate barrel steel melonite seems like a superior finish as compared with chrome lining, but lets not let this thread get hijacked about that discussion
If you choose you MUST coat the BCG then use a PVD (physical vapor deposition) coating such as Nickel Boron and Tungsten DLC (WDLC).
These coatings would also work on your gas tube.
Not sure it’s needed. If they were $15 and $2 more for the parts, respectively I’d take them but I’ve thus far not been sufficiently concerned enough to spend the money to have it done to existing parts, to be honest.