Heavy13 is a turkey shot made by environmetals (heavi-shot people). It's veeeeeeeeeeeeery sim to their heavy shot.
If your double patterns well, I'd use it. A SxS sit's nicely on your knee when your sitting under a tree

Stuff it with quality plated/buffered shot. Here in Mich we can use nothing bigger than 4 shot.
And for the record, I did whack a hen during the fall turkey season (incidental when duck hunting) with 3" steel #4's out of the before mentioned cabela's full choke. Killed her GYD at 30yds.
I have killed lot's of non-waterfowl game with 3" steel #4's - if it's in season - in range -

Gary