I've just purchased a hw100
I've heard some argue that heavier pellets do well on PCP and lighter in springers (or the other way around...hahahaha), but dont quote me on that.
btw, lighter pellets are more screwed in crosswinds, something else to think about and another reason why a little extra weight helps in the practical field sense way. If you're hunting, you need to think about a lot more in this sense
This is not quite try depends on BC of the pellet and a lighter pellet is not in the air as long .
Test have been done which shows a .177 pellet takes less wind than a .22