I'd personally definitely try them. There's not purpose that they'd not get the job done just high-quality in the Beeman. I've had excellent luck with RWS pellets in all of my airguns (Hatsan, Crossman, Benjamin and so on.). I might test a tin and see how your Grizzly likes them https://super17766665.angelinsblog.com/35062241/not-known-factual-statements-about-super177