BB didn't work well for me for fox with the 20 bore. That was likely due to the #4 buck shooting closer with more pellets on-target or just being more effective overall from my gun. IIRC, it shot poorly with the Imperial BB loads (paper case).

After a couple years, I bought, then switched to using my 6.5 Mag. for foxes as we only shot them for bounty ($5.0 Oxford County, $4 in Middlesex County) - the size of the hole made no difference. In the farmland of Southern Ontario where I grew up, they were just classified as vermin.

Here in BC, foxes are classified as fur bearing animals and as such, they can only be shot or trapped by a licensed trapper on crown land, or his licensed trap line.