The fields here can be for profit. Hardcorps in Pentiction had a great following.
So to add; sign up on the local Kelowna and Kamloops forums and then do a road trip to play in the area.
Expanding on why "field" BBs are looked at with distaste. Some players will spend a lot of time setting up their hop to be consistent and accurate with a particular brand and weight. If you can't run that same ammo on game days there's a high degree of frustration.
http://www.airsoftkamloops.com/
http://www.airsoftkelowna.ca/
Also an airsoft field needs to be an airsoft filed. No paint debris and sludge.