[Jimski]

you need a base coat of very gloss black before applying the metal shade.
the gloss paint has to be uber mega-micro-smooth if you want the mirror effect to work.

I haven't tried the krylon crap but most gold and chrome spray wont work unless they have a mirror cap and there's mentionned somewhere 'mirror effect' or some variation.

You need to polish your base black like a motherf**er, I'm not talking one coat and some varnish, you need to spray one coat, sand it, respray, resand, etc...anally again and again until achieving super-smoothness on the black coat.
Then you can do the same with the gold effect until you reach awesomeness in a tube.

to do that on a gun I'd probably stick a polishing broomhead on my drill, something fluffy.