I decided to take out my old single barrel 410 to have some fun shooting clay pigeons. One box cost $14.00 locally in the same store where I can buy cheap 12 gauge for $5.50 I have some steel shot 410's, the hulls have steel printed on them. I guess you could try a magnet to make sure.
Phillip McGregor (OFC)
"I am neither a fire arms nor a ballistics expert, but I was a combat infantry officer in the Great War, and I absolutely know that the bullet from an infantry rifle has to be able to shoot through things." General Douglas MacArthur