I wouldnt bead blast it. Id use aluminum oxide and blast with that. I would only do it if the finish is defective. If its just got nicks and scrapes, you can sand it with fine sandpaper and then duracoat it. The duracoat will adhere nicely to the anodizing. I have blasted receivers to bare metal and refinished them with duracoat and achieved excellent results. I am aware of the controversy regarding the hardening properties of anodizing. Im just stating my experience with projects I have personally done.