Yeah, there are thousands of internet posts on how to powder coat bullets. This link is geared toward powder coating in general, not merely bullets.
One problem I ran into when ESC'ing rifle bullets that were standing on a metal base, was that powder did not seem to be attracted to a "dead zone" on the part of the bullet closest to the metal base. The link explains that I was not imagining things, that these "dead zones" are called "Faraday Cages" in the PC trade, and they typically occur in recessed areas.
Many ESC'ers like to prop up their rifle bullets,standing them on a screw head or sticking the ogive into an empty cartridge case. I'm guessing that "propping up" the bullet may move the bullet away from the "Faraday Cage" area?