I know that I have to pattern my guns with different loads and to use what works best and to learn my limitations and stick to them, but. My only choiceis a Mossberg 500 20 gauge with a modified choke and a Savage 20 gauge single shot with a full choke. Whichever gun performs the best I'll still have range limitations over the average turkey hunter, I'm thinking probably about 30 yards max. With this in mind what is the smallest pellet size that will remain effective at 30 yards. I'm thinking that number 6 shot will get the kob done but could you use 7 1/2 hevi-shot? If anyone else uses a 20 gauge I'd like to hear your thoughts.