[Hectic]

For indoors the hop up wont matter as u likely wont have enough long rangez for hop up to take effect.
Plus for indoor you should use 20's for safety.
If your playin outdoors youll wanna use 28's on a 350ish fps setup and 30's above that. And even on a 350fps setup if your hop up is good enough (like a bagon or promy bridge or rhop) youll wanna use 30's or 32's
If your in a place with higher limits maybe even heavier. At 420fps plus you can even run 36's if your hop up is capeable of it. But 30's or 32's are fine. Most folks run 28's or 30's for outdoors.
I run 32's at fields that use BIO bbs and 30's every place else
Much better accuracy and range on all my guns from 350-400fps. I use 36 of 40 on my 500fps bolt action.
Heavier bbs will carry energy longer/further will not be effected by wind hot or cold spots or humid spots as much as light ones and will be better at cutting through brush and such too