RE: just got my Indian Creek Black Diamond Strike choke tube today...
I just got an Indian Creek .555 for my 20 gauge and I was impressed!
The Winchester Ext. Range #5's patterned a little better than the Hevi13 #6's, I settled with the Wins because they are faster and 5's instead of 6's.
I shoot 6 shot out of my 12 gauge all the time, and have killed tons of birds with it.