My husband works with wood a lot. He makes rifle magazine loaders that get a lot of abuse. He found a finish that beats anything. It is called a Spar finish, and is made by Helmsman. We have used both the spray on and the liquid. The stuff is made to be used on the wood parts of boats, so it has to be tough. His demo loader has had thousands of rounds put through it and not a nick or scratch any where. He also waxes them with paste wax to protect the surface even more. One can would probably do what you need. And it runs between 8 and 10 bucks depending where you buy it.