Also - the Longbeard XR choke (manufactured by Carlson) designed specifically for the Longbeard XR shot has a constriction of .660 or .665 for most guns.

In my experiences the denser-than-lead shot typically pattern a bit better from a more open choke. You may find the best patterns from a cheaper lead or copper-plated lead shot through that .655 constriction - I would recommend you also look at the Winchester XX or the Federal Grand Slam.