Couple weeks. hell I'm on here almost everyday dreaming of huntin' turkeys
As Adrian said I have had awesome success with my Indian Creek out of my 1300. It is after many experiments with many shells however and careful care and cleaning of my gun during patterning. There is an amazing difference when I change ammo and even when I change the prodcution year for the same ammo. As mentioned it needs to be the white shelled Hevi-13 in #6 for my gun and Indian Creek choke. When using the new bronze 2oz Hevi-13 my pattern was very poor past 35 yds.
I think you'll be fine but expect to try a few different loads. Also if your not polishing your barrel it will not yeild effective results after shooting at the range for a patterning session.
I always made sure I was testing each shot in the same controlled scenario. Clean the barrel, let the gun cool, use a rest. I have seen guys pump a shell into thier dirty gun, fire a shot offhand and then say "man, that choke sure is no good in my gun".
By the way there BossTom. I want to be there for that patterning session

12guage versus the 20 guage for a bottle of CR