Try some Brownells spray on then bake on coating. I've got some, but havent tried it yet, and the guy at work that gave it to me says his .45 slide coating just gets tougher as time goes on. It may not work on internal parts, and sand or bead blasting are recommended for best results, so you'd have to take apart any individual pieces to avoid damage to surrounding areas. I dont really know what the Jackal looks like, so you'll have to decide if its worth the effort.