Hi,
Here's a wrinkle. I think the powder coating (PC) could be used on FMJ projectiles too. The reason is proper projectiles for the 6.5mm Carcano are limited. 160 gn FMJRN and RNSP. Carcano requires a .268 inch diameter projectile. All 6.5mm ,Swede etc, are .264 inch diameter.
The PC could add enough diameter to engage the rifling properly.
To prep the copper jacket I would acid wash the bullets with a vinegar, concentrated lemon juice, and Dawn dish detergent solution. This is excellent for cleaning brass, steel, and as well bullets! I think cleaning/etching the copper jackets would give the PC a better chance to stick.
Would it adhere well enough to survive higher pressure/velocity?
Thoughts/ideas would be appreciated.
The Ammo Guy 8-)
Aim small, miss small.