I have only used Dura Coat but here is what i have found so far with it.
If you order the starter kit from Dura Coat they will send you a cheap air brush with a connection to a canned air bottle, if you are serious about wanting to do it i would recomend you buy a decent airbrush with small compressor, it will work alot better. As for degreasing the parts i have had good luck with Hoppes Gun Scrubber, it has a powerful blast and works well. When painting the metal parts make sure they have some texture to them. ANy kind of matte finishing will work well. As for the bolt on most of the rifles i have done the bolt sleeve is usually very smooth, i would imagine emory cloth or some kind of fine made for metal sanding paper would work good. Also make sure you degrese the bolt very well, some of the internal grease can cause paint not to stick. I have never disasembled a bolt for painting but i would bet that would work as long as you watch what parts you paint. As for brakes i have painted a few and with the simple spray on dura coat i have not been able to get the paint to hold on to the parts of the brake that the high pressure gasses hit, but this has only been in large colume rounds. If you are wanting to do some kind of custom pattern i have had the best luck with simple masking tape, some other stuff has pulled paint off of under layers.
And on a last note, wear a mask and find somewhere with some good ventaltion, that stuff can get you goin in a bad way!!! Also do several layers on any parts that will recieve the most wear.
Third Generation Shooting Supply
"Products for shooters, by shooters"
monday-friday 8:30-5:30 CST