DLC on bolt lugs & for the receiver lugs I don't know? The coating can take a lot of pressure (400,000 psi) so maybe just limit coating build up to about .001. That way even if you managed to completely wear it off (not really possible) your only +.001 on head space.
The Fluoropolymer coating is kind of an oddity in it's properties & we're not used to thinking about coatings like this.
My choice of words "sacrificial" kind of implies soft, but it's not.
It does not wear or de-bond easily. It actually penetrates the base metal i.e. bond goes below surface. What makes it pretty unique is it's ability to allow small hard particles to embed instead of lock things up.
Think of it this way: Even with a hand full of sand (silica particles) embedded in the Fluoropolymer you'd still have maybe 10% hard on hard wear surface vs 100% when you've got both bolt and receiver DLC'd or Nitrided.
Alternatively you could mask the receiver lugs leaving the base nitride, but that would kind of defeat the potential to re-coat & return the entire receiver to original spec.
It would still protect the DLC bolt from wear as well as the receiver raceways + run slick and reliable in adverse conditions.
Hoplite is pushing the envelope (Bravo!), so I'm just positing thoughts to that aim.
I've got some other ideas surounding the use of ceramic's for the high pressure rounds, but that's down the road.
