Every gun is different. But in the 3 Winchester 1300 guns I've used my undertaker in likes the #6 shot. Wouldn't pattern the bigger stuff. But I got very good patterns with #6 shot. In fact I got my best patterns with 2 3/4" #6 shot.

The best all arounf choke I've had in my 1300 is the Tru Glo strut stopper my a narrow margin over the Hastings .665 turkey choke. The Hastings choke is defintely more reasonable the the Tru Glo choke.

Good Luck!