What coating would you put on the bolt lugs and the action lugs?
they take the hardest beating
if you use the sacrificial coating either the bolt lugs or the action lugs “will shrink” after every cycle (although it may take time) changing chamber dimensions.
or possibly wearing uneven and causing one lug or a part of one lug taking all the force.
thanks
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.On second thought possibly the bolt lug mating surfaces might need to be skimmed off? Not sure since the coating will take up to 400,000 psi.
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.