Make sure the powder coat you’re using does not contain Teflon.
Here is the Wikipedia info on it. http://en.wikipedia.org/wiki/Teflon-coated_bullet
Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. The best known brand name of PTFE-based formulas is Teflon by Chemours. Chemours is a spin-off of DuPont Co., which discovered the compound in 1938.
PTFE is a fluorocarbon