I did a quick topic about water immersion camo on here somewhere if you can find it that may help if that's the route you're going.
Since the gun will have to be painted before you do the water dip in the film, cerakote is a good choice for that. Although if you have the equipment to airbrush and then bake in the oven, I like either KG GunKoter or Norrell's Moly a little better than cerakote, but if not, the cerakote is one of the good alternatives.
And to be honest, a light tan color base coat on the gun gave me the best outcome when you dip the camo.
If you have any questions, I'd be glad to help any way I could.
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