Seems amazing to me that a whole industry has been created for specialized screw in chokes for guns that basically already come with the 3 standard chokes that can do pretty much everything. Seems everyone has forgotten that in the 60's most everyone had a modified choke, screw in chokes didn't exist and people were actually capable of killing turkeys with 2 3/4 inch shells, but I digress.
If you listen to all the hype today, you need a extra extra extra full specialized choke(must be very expensive to work properly also), and a magical 3 to 3 1/2 inch shotshell to kill a turkey, but again I digress, LOL.
If I were you, I'd screw in the full Winchoke that came with the gun, get yourself some 2 3/4 mag or 3 inch mag shotshells with the shotsize of your choice, and take the time to pattern the gun, out to 50 yards to see what it does. I think you'll find the full choke just fine, you just need to pattern it, every barrel is different and patterns differnt shells differently.
What do I use personally in my 1300's? I have 2 in 12 gauge with a 28 & a 26 inch barrel. I use the Winchoke full chokes that came with the guns and Winchester Super X 2 3/4 inch mag loads with 1 1/2 ouonces of #4 lead shot.
Woodsmanship, scouting, and knowing your quarry kills turkeys(and anything else for that matter), not an extra extra extra full choke and magical shells.
Shot my first turkey in 1970 at 40 yards, near Snowshoe Pa. with the only gun I owned, an Ithaca 37 12 gauge, 28 inch barrel with a modified choke. I couldn't unscrew the modified choke and put in the full choke, because it was a fixed choke barrel. I used a Winchester 2 3/4 inch magnum load, 1 1/2th ounces of #4's purchased for $3.65(I still have the original box and 15 rounds left in it). Just plain lead, no magical plating, etc., 4 pellets in the head and 5 in the neck, bang flop, dead turkey. I have a friend whom I saw shoot a turkey at 35 yards with a Remington 1100, modified choke. He couldn't unscrew his modified choke either and put in a full choke because it was a fixed choke. He used an AA trapload, 1 1/8 ounces of 7 1/2's, bang flop, dead turkey.
