I would undoubtedly attempt them. There may be not motive that they'd not function just great within your Beeman. I have had good luck with RWS pellets in all of my airguns (Hatsan, Crossman, Benjamin etc.). I might consider a tin and see how your Grizzly likes them as all https://super17767666.angelinsblog.com/35061223/not-known-details-about-super177