If it has not been tried at the pattern board yet, that could be a good step before choke work. A western duck gun can be pushed out to deceptively long ranges. If the bismuth are hand loads, might consider dropping an eighth of an ounce, if the patterns are actually too dense. In my mind, it does not really mattering if it meant a few less ducks over a season. By chance, I’ve happened to do the majority of my recent practicing at fairly close range clays with f/f guns, plenty enough fun and doable.