If you use Krylon, you might try giving it a coat or two of satin polyurethane over top. I tried using Krylon 1311 matte sealer on my Kryloned shotgun, but it seemed to dissolve under the effects of solvents, lubricants and remained tacky for some reason. I cleaned that off and sprayed it with the first coat of satin polyurethane to try this waterfowling season.
Don't know how durable it will be, but it's likely better than just the Krylon. I know using the matte 1311 helped, despite it's deficiencies.