So you are a soldier or police or you just have a real desire to be super stealthy at night from an enemy that might have night vision optics? This video shows special cerakote coatings you can have done to your weapons that will help hide the weapon from infrared vision sights.
Watch the guy crawl like a spider up to his invisible weapon, you see the guy but just try to see the rifle.

If you do this to your gun for God's sake you probably don't want to ever drop it in the bushes by mistake, you will probably never find that damn thing again.