I might unquestionably test them. There is not reason that they'd not do the job just great in the Beeman. I've experienced excellent luck with RWS pellets in all of my airguns (Hatsan, Crossman, Benjamin and so forth.). I might test a tin and see how your Grizzly likes them https://johnathannanxo.blogdun.com/36688215/not-known-details-about-super177