i have 81 range and i've been thinking if chimpchops at cw on the offical cw world would be good to level my range. Did anyone try that?

It won't be as good compared to the power-training methods, however it wouldn't be bad experience.

Yeah, theres nothing like 10 skeletons all around you unable to do a single bit of damage (if you have prayer I hope) with tons of hp, respawning more and more every second.

Most people wear melee armour at cw which has good ranged defence so I don't think you'd hit very high.

You'd be better off firing them at the monsters near the portals in PC. But CW will work.