Never, never, never use carb spray on firearms. It's way too harsh. It can and will destroy plastic parts, and can discolor certain metals, as well as destroy the bluing.
Matter-of-fact, I never feel the need to use any harsh chemicals on firearms. I use Hoppes #9 on the bores, and Rem Oil to lubricate.
I'm just not a big fan of a pressurized spray can with a small straw stuck in it.
One of the best things I've found to lube a firearm with, is an old-style shaving brush. Just a few drops of Rem Oil on the bristles and it applies a perfectly light coat of oil to the surface. I actually have two brushes. One for dusting off and one for lubing. Don't get them mixed up though. The shaving brushes can be very hard to find though. Most of the small(er) drug store type businesses carry them.