Carlson Sporting Clays 12 Ga Choke Tube Win Brown Mossberg Light Modified. Our NEW Sporting Clays with a BLACK FINISH 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% longer parallel section in the choke thus throwing more consistent patterns than conventional choke tubes. Each choke tube is knurled on the end to allow for quick and easy removal or installation. Each choke has the constriction lasered on the end for easy reference.