NOT KNOWN FACTUAL STATEMENTS ABOUT SUPER177

I'd personally definitely try them. There's not motive that they might not get the job done just great in the Beeman. I've experienced fantastic luck with RWS pellets in all of my airguns (Hatsan, Crossman, Benjamin etc.). I would try a tin and find out how your Grizzly likes them as all guns appear to have their beloved pellets.Umarex 12 Gram CO2