Painting using spray cans/pressure packs

Guys,
Im after some general painting advice, particularly using pressure packs. I can get a reasonable finish using a pressure pack but no matter how well I seem to prep things I always have some kind of orange peel effect in the finish. Here is an example:

This was stripped to bare metal, hit with 180, primed, 320'd then 400'd then 600'd, then 2 coats of colour.
How would you take this to the next level of nice glossy finishes? Hit it with some 1200? 600? A cutting compound?
Any tips appreciated...
Im after some general painting advice, particularly using pressure packs. I can get a reasonable finish using a pressure pack but no matter how well I seem to prep things I always have some kind of orange peel effect in the finish. Here is an example:

This was stripped to bare metal, hit with 180, primed, 320'd then 400'd then 600'd, then 2 coats of colour.
How would you take this to the next level of nice glossy finishes? Hit it with some 1200? 600? A cutting compound?
Any tips appreciated...