Non-toxic dove loads are steel #7 and #6. Texas Game Commission did a study around 2008 (managed by Tom Roster) that found an ounce of steel in either size killed the same percentage of doves per shot fired as 1 1/8 oz of lead 7 1/2, the most popular load. The study was double blind, which means neither the shooters nor the observers knew what they were shooting. The cartridges were identical in appearance.

I bought a flat of steel #7 from Bass Pro Shop for $100 last summer, to use in a public dove shoot area in which non-toxic shot is required. I don't shoot them in old doubles, of course. I have a modern gun with fixed IC choke for such occasions.

Caution: Hunting and fishing stories told here. Protective footgear may be required.