I'd definitely attempt them. There's not purpose that they would not function just good inside your Beeman. I've had excellent luck with RWS pellets in all of my airguns (Hatsan, Crossman, Benjamin and so forth.). I'd attempt a tin and find out how your Grizzly likes them as all guns https://super17711111.win-blog.com/16705566/super177-can-be-fun-for-anyone