I'd definitely try out them. There's not explanation that they would not function just good inside your Beeman. I have had good luck with RWS pellets in all of my airguns (Hatsan, Crossman, Benjamin etc.). I might try a tin and find out how your Grizzly likes them as all https://super17734455.dailyhitblog.com/41416339/details-fiction-and-super177