I have an Undertaker choke designed for Hevi-shot. It is called the Undertaker H.S. The H.S. is on both the choke and the package. It states right on the packaging that it is "for use with Hevi-shot loads, Bismuth & Tungsten Matrix".

On the back of my packaging it lists the Hevi-Shot inside diameters for the different shotguns. All but one are listed at .675 with the exception of .705 to be used in a Mossberg 835.

Hope this helps.