Sporting Clay ChokesSporting Clay chokes are made from 1704 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, Copperplated, Nickel, Hevi-Shot, Bismuth, tungsten or steel shot may be sued in these choke tubes. Each choke tube is knurled on the end to allow for quick and easy removal. Each choke tube has the constriction laser marked on the end for easy reference.For best results, pattern your choke tube with the specific shotshell load you will be using in the field. Different brands of ammunition pattern differently from the same choke tube.