Our sporting clays choke tubes are made from 17-4 Heat-Treated stainless steel and precision machined to produce a choke tube that patterns better than flush mount choke tubes. These choke tubes feature a 25% longer parallel section in the choke thus throwing more consistent patterns than conventional choke tubes. Lead, copperplate, nickel, heavy-shot, Bismuth, Tungsten or steel shot may be used in these choke tubes. For best results, pattern your choke tube with the specific shot shell load you will be using in the field. Different ammunition patterns differently from the same choke tube. These choke tubes are backed by our lifetime warranty.