Still looking? Try:
Stittsville Shooting Range
That Hunting Store in Richmond
The co-op in North Gower
Sorry, I don't have contact info for any of these with me right now but you can find any by doing a quick internet search.
I would not recommend 16g buck for deer as it only comes in #1 buck. I had a very bad experience using this at under 30 yards on a coyote. Basically it would not him down but not penetrate. When we skinned him there were more than a 20 pellets wrapped up in his fur & numerous bruises where pellets hit but wouldn't penetrate. These were new Winchester shells and I was using a 26" barrels chocked IC & M.
16G slugs work great on deer.