I would use smaller buck shot out of which ever gun shot it best,I dont think I would try it out of a rifled barrel,it might be OK I dont know never heard of it,You might check your state regs. about buckshot some states dont allow it.one of your smoothbores should shot it good get some posterboards from the store and pattern them,you should be able to shoot upto around 60 yards and have enough pellets hit the vitals to kill'em,good luck!!