Choke Recommendations for 835 and HW 7's

[Spurs Up]

Anybody got first-hand experience and a good recommendation for a choke to use with a Mossberg 835 when shooting 3 or 3.5" Fed Heavyweight #7's???

I've seen suggestions that are all over the map.  Open choke (>0.690) to super tight (<0.670) choke.  Ported and non-ported.  But...very few that are backed with reported results.  Hopefully somebody's found a combination that consistently exceeds 200/10/40.  Thanks!