As a matter of interest I bought some Gamo "Raptors" in both .177 and .22. Haven't tried the .22s yet but the .177s simply don't work in lower powered CO2 guns. I tried them is my S&W 586 and they just jammed up the action. Same in a SIG MCX. It seems they are too hard (or large) to enter the barrel with the relatively low energy from these.

I'll probably use the .22s in a springer but if anyone wants the .177s you're welcome to them.