drh you won't want to shoot ANY of the lead alternatives in that choke tube. A .655" is simply to tight for any of it. Try and stay above .665 with .670-.695 being typically the best for the heaviest loads.

Environmetal is the actual creators and patent holder for Hevi-Shot. Remington had a 5 year exclusive on it and that expired lastyear. That is EM is now marketing their own. Rems Hevi-Shot IS better than lead, but it is a far cry from the Nitros. But you probably will have to get a new tube and experiment with a few loads to really "dial er in".

The stuff works tho!
RA