I'd personally unquestionably try them. There is not reason that they'd not operate just wonderful with your Beeman. I have had good luck with RWS pellets in all of my airguns (Hatsan, Crossman, Benjamin etc.). I'd try out a tin and see how your Grizzly likes them as all guns https://archerfvjpc.getblogs.net/68515929/the-definitive-guide-to-super177