Reloading buckshot supplys need info

[mrcrossbow]

Good morning all.
I'm looking for some #4 buckshot. Just the lead balls. Makes great, great slingshot ammo. I just can't seem to find any. Like 5lb boxs or more.
Why #4. Well I cut open a bunch of my shells and tested the different sizes and number 4 buck flew best with double bands. Was getting pass thoughts at roughly ten yards on gophers.
Worked on rabbit just as good. But 50 cal rounds worked even better. But that's easy to find at Cabela's. Gosh now I'm rambling. So yes need number 4 buck. Loose. Any place that sells it.. In Calgary be awesome but hey if I got get it shipped and pay shipping then so be it.
Thank you muchly for any help. Gents or lady's.