NOT KNOWN DETAILS ABOUT SUPER177

I would undoubtedly try out them. There exists not explanation that they'd not work just good inside your Beeman. I have experienced superior luck with RWS pellets in all of my airguns (Hatsan, Crossman, Benjamin etcetera.). I'd personally attempt a tin and see how your Grizzly likes them as all guns appear to have their most loved pellets.Umarex 1