Unless you are a conscientious objector to the use of any shot other than lead, you might reconsider your commitment to using only lead. If it is a cost concern, you don't have to buy a box of 25 shells when buying Federal Heavyweight shells as they come in boxes of 5 or 10 which will lower your initial cash down. Federal HW 7s and a Sumtoy are bad medicine for turkeys out of a 20 gauge rig. Now dead is dead and lead will continue to kill plenty of turkeys but with the HW-7, out of your 20 gauge, you will have the effective, ethical killing range that one would have with a 12 gauge 3.5" shell shooting a max load lead.