gosh
Man, its SEPT, but if we're gonna talk spring gobbler, I'm in.
I'm a 12 ga guy myself, never killed a bird with the 20 ga. But there are some guys of my acquaintance, good turkey hunters, who are carrying 20 ga's, especially once the leaves come out and ranges tend (sometimes) to shorten.
They bought'em for their kids, liked how light they were, and saw the kids kill birds with them, and took them up themselves.
Each and every one shoots what I call space shot, the new space metal alloys, "hevishot" or its equal. Expensive, but a big jump up from lead in range and penetration. I will get flamed for this, but if I we're gonna hunt gobblers with a 20, I'd invest in space shot. As I know very little about space shot sizes, I'd want the equivalent of lead #5 or 6, so I guess space shot size 6 or 7-1/2.
It certainly is called hunting and not killing,and I will tell you right now that if you are like most of us, you will hunt spring gobblers alot and often, before the occassion arises now and again to kill one. For that reason, I am very picky about my guns, loads and performance. After all the effort, and nothing else goes wrong, and a tom presents a shot in range, I don't want a marginal rig. And, in those instances when things do go right, some birds do "come right in", but not all. Some hang or alert right at the edge of what your shotgun can reasonably do. And there are all sorts of stuff in the woods that can strip pellets out of a pattern on its way to a bird. That dense cluster you got on the pattern board may not be what arrives at your gobbler. For all that, I'd go with a 3 inch shell and space shot or very premium lead.
A 3 inch twenty (lead) delivers the payload, and I'd guess the performance, theoretically, of the old standby 2-3/4", 1-1/4 oz 12 ga lead load. I killed my first few gobblers with a std 12 ga and plain old fixed choke full, and they got very dead. The ranges, if I recall right, were 30 yds and under, one for sure, 'bout half that. With advanced chokes, space shot and sights, the 3" 20 ga can only improve on that old measure.
I'd set my limit at 35 yds, shoot 3 inch shells, prefer hevishot but accept good patterns with #6 lead, know my gun and load and have at it.
The 20 cannot equal the big 12's, but is demonstrating enough wallop in its new and improved state, to take birds at the time honored ranges.
You're gonna love spring gobbler hunting. One set up and you are ruined.