I'd personally definitely try them. There's not purpose that they would not get the job done just great in the Beeman. I've experienced excellent luck with RWS pellets in all of my airguns (Hatsan, Crossman, Benjamin etc.). I'd personally attempt a tin and find out how your Grizzly likes them https://super17790900.blogdanica.com/35982296/super177-can-be-fun-for-anyone