Tons of great advice already and you can experiment with almost endless combinations. I would say that you will probably find a "square" load or slightly more shot than powder will give best results. Since max range will be no more than 25 yards, I lean toward #6 shot for best pattern density.
I've shot more than a score of gobblers with a cylinder bored Caywood .62 using 80gr. 3F and 1 1/8oz (by volume - equates to roughly 100gr. volume equivalent if I recall) of #6 lead. I prime with 4f mostly when hunting, but am just as comfortable using 3f. My max "for sure" range is 20 yards and of all the birds I've kilt, one was at about 23 paces and the rest were inside 15 (the vast majority at 10-12 yards which is where I set my decoy). After experimenting with different loads as high at 100gr. powder and 1 1/2 oz. shot I found best results with the moderate load I mentioned. And after testing paper shot bags/cups, plastic wads ( :barf: ) and various lubed/unlubed fiber cards I found that powder, 4 thin o/s cards, shot and 1 o/s card to hold it in worked great for me and the simple ingredients are easy to keep on hand. Every time I used heavier wads over the powder, I got "doughnut" patterns.
For me, there is nothing more gratifying than getting up close and very personal with a big tom and using my flinter to take him home. Have fun! :thumbsup: