Hevi-13 - 20 Gauge - Win-Choke
The 20 Gauge Hevi-13 Win-Choke, also known as Invector Choke and Accu-Choke system fits Winchester, Browning Invector, Mossberg, Weatherby Savagei and other guns using the Win-Choke system. These Turkey Chokes are precisely engineered for bee-swarm-dense patterning with Hevi-13 loads. They also pattern tightly with lead and other lead-alternative loads. Non-ported.
The exit diameter is .573