You might look into Dixie Slugs Tri-ball ammo for your 930.
"What is Tri-Ball 3"?
Tri-Ball 3" is a development at Dixie Slugs for 12 ga. 3" Magnum! It has 3-.600" hard alloy cast round balls/buckshot, gives a velocity of 1050+/-'/". It is classed a buckshot, albeit very large buckshot. The...