I am a certified or factory trained Cerakote applicator. Durakote prep is similar. The finish just isn't near as durable. A factory Remington 700 has very generous clearance between the bolt and the action. First soak in acetone for 20 minutes. Plug the muzzle and the chamber securely with rubber stoppers. Blast with 100-120 aluminum oxide thoroughly inside and out. Everywhere you want the coating and it is to your advantage to get as much coverage as possible to extend the coatings benefits everywhere you can. Cerakote has lubricating properties and it will be noticeably smoother in operation after the coating is finished. Blow it out good with dry filtered air. Preheat to 250 for 30 minutes to burn off and drive out any oils that may show up during cooking. If oil is noted you need to resoak in acetone and reblast those areas until no oil shows up when preheated. Now that you are fully oil free let it cool to room temp. Now mix up you coating and apply. I coat the bolt body, face and the lugs. Coat the action inside and out. Bake at 250 for 2 hours. Cerakote finishes at .0005" to .001" thick.
Things on a 700 I don't coat are the trigger assembly, the trigger hanger pins and the bolt stop return spring. I dissasemble the bolt and do everything but the firing pin spring and the very tip of the firing pin. You probably could but I just don't. If the trigger hanger pins fit loose I will coat them too. Everyone raves how much smoother there guns feel once I am done.