I thought it had to be baked on.
In order to provide good wear resistance, GunKote needs to be applied to chemically clean metal (they recommend abrasive blasting) with a surface temperature of 100 degrees, then baked on at 300 degrees for 1 hour. Cool, then your gun is ready for reassembly.
GunKote contains molybdenum disulfide (as a lubricant), suspended in an epoxy powder base with a solvent as the carrier. When you spray it on, it looks like paint but has only moderate adhesion to the metal. When you heat it, it melts the little beads of epoxy onto the metal, allowing it to bond strongly. I have removed GunKote from guns in the past, and if it was applied properly it has to be sandblasted off.