I'd unquestionably try out them. There is not rationale that they might not work just high-quality in the Beeman. I've experienced superior luck with RWS pellets in all of my airguns (Hatsan, Crossman, Benjamin etc.). I might attempt a tin and see how your Grizzly likes them as all guns seem to have their favored pellets.Umarex 12 Gram CO2 is clear