The Vintage Thompson Center Contender. 357 Barrel Choke is a high-quality steel barrel specifically designed for Thompson Center contender handguns. Made in the United States, this blue-colored barrel is compatible with. 357 Magnum caliber guns. With its durable construction and precise craftsmanship, this barrel is a reliable and essential component for those seeking to enhance their hunting or shooting experience. The Thompson/Center Arms brand ensures a level of quality and performance that is trusted by gun enthusiasts.