Finch is the most popular I think.
There is a field near Canada's Wonderland called Black Site, but I think it's private. I only know of it because there was an event posting here on ASC a little while ago. Don't know if they're still active or allow public members in.
Custom VFC M4 - KJW KC02 - KJW Mk1 - TM P226 - KJW M9