I'd absolutely consider them. There may be not motive that they might 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 try a tin and find out how your Grizzly likes them as https://super17700111.blogitright.com/36145693/the-2-minute-rule-for-super177