I realize this is not an AR, but this thread got me thinking about painting my coyote rifle. I taped the action, trigger guard and trigger, scope ends, and the grip inserts on the rifle, and I covered the muzzle with a piece of tape. I painted one coat of black krylon, let it dry, used my home made stencils (strips of masking tape cut into blades of grass in a sense), painted two coats of white paint, and then removed the stencils. Maybe not my best work but I am happy with it. As someone else pointed out, its made to be functional, not a safe queen.
Gen 2: 19,22. Gen 2.5: 36. Sig 226, H&K USP .45 OD. Sig Scorpion 1911.
Gen 3: 22, 22RTF2, 23OD, 21SF, 19, 19C, 19, 38, 42