Carlsons 13372 Remington Sporting Clay Sport Skeet .615 Choke Tubes, 20 Gauge Our sporting Clays choke tubes are made from 17-4 stainless and precision Machined to produce a choke tube that patterns better than standard choke tubes These choke tubes feature a 25% larger Parallel section in the choke thus throwing more consistent patterns than conventional choke tubes Lead shot, Steel Shot, Copper plated Shot, Nickel Shot, Hevi-Shot shells, and Buck Shot can be used in our Sporting Clay Choke Tubes