For them to be really useful, you'd have to have a supply of #12 shot. .22lr or mag loads of #12 would be better than any likely amount of #9 in a .32. You might go the gas-check route, but usually the expander plug for the next smaller bore is used to seat the lower check and I don't know if a .25acp plug would be long enough to work. You'd be on your own for loading data, but lighter powder charges normally work better than heavier ones even if the heavy ones are not over-pressure. If you do try it, test them on potatoes and don't shoot at anything hard enough to throw the shot back at you.