Powder coating is basically this: Electro-static paint in powder form. **
In reference to my Astra, I stripped the gun of all screws, springs, and anything else until I had just the frame. I then went to a bench-grinder with a wire brush on one side and a polishing wheel on the other. The wire brush stripped everything from the gun down to the bare metal. I then polished the bare metal until it 'looked good.'
A special powder coating gun is needed to use this type of paint. It requires an air compressor (regulated) to work the paint gun. A ground lead is attached to the stripped metal while the paint gun is "positively charged" via a control box for the paint gun. As the trigger is pulled on the paint gun, a powder lightly flows from the gun and attaches itself to the grounded metal. (Opposites attract) The powder covered metal is then baked in an oven. The baking process is what turns the powder into a liquid. After baking and letting the metal cool off, you're done.
Do make note that many people frown on this practice with guns.
I took pictures of the whole process and will post them when I remember to bring the photos home.
**I'm no expert on this and I'm sure someone can clarify what the heck I'm trying to say.