In the next couple weeks i'm going to take the plunge and krylon one or all of my rifles. I've found alot of threads about how to spray everything, but what about prep? Acetone? Any problems using it on my magpul stuff?
Acetone will work fine. Just make sure it is all flashed off before you paint. And handle with latex gloves so you don't get your greasy paw prints on it just before you spray either. Magpul parts should be fine. I recommend the fusion paint, I use that for all my spray paint needs, gun related or otherwise.
Surface prep for Krylon is like bringing flowers to a hooker.
I mean, you could do it, but what's the point?
If you actually use the rifle, Krylon is not going to be very durable and very sensitive to solvents (like CLP). If you're looking for a more durable finish, I would look into something like Duracoat or Cerakote.
That being said, any de-greasing should work, you just want to get the surface clear of all oils that will negatively effect the adhesion of the paint.