Nickel is also a component in hevi shot. Some chokes designed for hevi shot are the Undertaker, Primos Jellyhead, Briley makes a hevi shot choke, Tru Glo Gobble-stopper xtreme, Pure-Gold, and MAD Super Max. Make sure it says it't hevi shot compatible before you buy it. I use the Jellyhead and it works great for me. It costs $40 to $50. The MAD Super Max is going to cost you $75 to $80. The hevi shot compatible undertaker is about 20 bucks, but is a good choke for the money. Just make sure it's the hevi shot undertaker. They make several types of undertakers.