Introducing Carlson's innovative new Bismuth bone buster Choke Tubes, meticulously crafted to achieve exceptional, concentrated patterns using any Bismuth ammunition. Engineered through CNC precision machining using 17-4 heat treated stainless steel, these tubes showcase an elongated parallel section within the Choke, surpassing conventional factory versions. The culmination of rigorous trials involving diverse loads solidifies these chokes as the ultimate solution for unleashing devastating Bismuth patterns. Offered in mid range (with .025 constriction) and extended range (featuring .035 constriction), these chokes accommodate lead and Hevi-Shot loads seamlessly. While the mid range variant is compatible with all steel shots, the extended range version accommodates steel shots up to size #2. Immerse yourself in the realm of unparalleled pattern density and bone crushing power with the all-new Bismuth Choke Tubes from Carlson. Moreover, these chokes are accompanied by Carlson's unwavering lifetime warranty, ensuring enduring performance and peace of mind.