Dealing with thermal shock / high temps

[AresP]

Gents,

a blued shotgun barrel is beginning to rust. Elements of oxidation have reached the surface and are plainly visible. The owner thinks that black chrome would look very cool. The shotgun is rarely used.

If I strip the blueing and then proceed as normal with cleaning, buffing, polishing the base metal and then go flash copper and black chrome on it, will I lead myself to embarassement when the shotgun is used and temp starts to rise by having all the work delaminate ?

In general, I am a little sceptical regarding the resistance to high temps of the flash copper/copy chrome of black chrome combos. I am sceptical not because I have seen otherwise but because simply I have never tried them on pieces that heat up, like exausts. Is the statement "the higher the temps, the thicker the plate" true ? Caswell suggests a 0.005" plate thickness for outdoor/motorsport applications. Is that recomended thickness for room/low temps or the same thickness can be applied to higher temp pieces ?

Regards,

Ares