SUPER177 NO FURTHER A MYSTERY

I'd personally definitely try them. There's not purpose that they would not get the job done just great in your Beeman. I've experienced fantastic luck with RWS pellets in all of my airguns (Hatsan, Crossman, Benjamin and many others.). I might try a tin and see how your Grizzly likes them as all guns appear to have their most loved pellets.Umarex