NOT KNOWN DETAILS ABOUT SUPER177

I'd personally unquestionably try them. There is certainly not cause that they'd not operate just wonderful within your Beeman. I have had great luck with RWS pellets in all of my airguns (Hatsan, Crossman, Benjamin and so on.). I would attempt a tin and see how your Grizzly likes them as all guns appear to have their beloved pellets.The RWS Superd