You know what looked really cool? When i improperly layed down my first can of paint on my m4 last summer, I had to wipe it all down but some was still on there and in cracks and it had a very "dirty" look to it, like it had just got back from the sandbox, might be an inspiration.
I see what you mean, but. . .no.
Rifles that just got back from the sandbox are cool because they just got back from the sandbox.
Faux finishes on rifles is about the worst exemplification of
poseur I can imagine!
With regards to heat dissipation, I doubt it would have a noticeable effect. Were talking a fraction of a millimeter here. Several coats might make your barrel maintain a few degrees longer than without, but that will hardly affect anything.
If you want to fret about rifles and painting them, do it when you get around the sights, mag well, and bolt carrier/cover. You could put 3+ coats of krylon on an issue M4 and it won't behave much different, but you guys wanna worry! :lol:
Like Mark said, the paint cracks off after use. Around the barrel (and on the barrel itself), and the front of the upper receiever, it gets very hot from firing. With normal spraypaint, this causes the paint to become brittle and lose it's elasticity. It then comes off in small flakes.
Some cleaning solvents can cause paint to come off, but CLP has little effect once the paint is fully cured.