turkey patterns
Hello pollo.
Will echo some of what has been stated already. You don't need hevi-shot to kill gobblers at reasonable ranges ( 40 yds, +/- ) "Space shot" is an undeniable improvement over lead, but the advantage it offers is over sold by the ammo companies and industry if you ask me. And you don't need 3.5" shells either.
Once the leaves come out, it is often difficult to see birds in a woodland setting beyond the 40-45 yd range anyhow. Many thousands of gobblers have fallen to lead shot. Modern lead loads , decoys, calls and blinds have all combined to allow us to get gobblers in reasonable range. My shots on birds last year were taken at 39, 39, 33 and 20 paces, and all got plenty dead with plain old lead.
I've never found a load with lead #4 that patterned well enough to use it as a first round up in my old 870. Always shot just a bit thin. Most guns will shoot #6 lead well enough, but range estimation is a bit more critical with #6's. I feel #5 lead is a good compromise...but all guns/loads need patterned and are a study of their own. Be sure and have some type of sights beyond the old single bead.
I use a plain sheet of typing paper as a target, with a hand drawn gobblers head on it for grins. I count pellets with a magic marker, and label and save same. My early turkey gun, my grandad's Savage pump, with std 1-1/4 oz loads, would put about 70 - #6 pellets on a sheet of typing paper at 30 paces. Modern guns and lead loads will easily double that, often with larger shot! The 870, and bamaboys 835, will put 150+ #5 shot from a hi-vel 3" mag, on that same piece of paper. I've got a sheet shot with the old 2-1/4oz Active load, #6 shot, that has an incredible 181 pellet holes in it!
Get some sights, swap for some 3" shells with a pal, experiment with make and shot size, don't expect high pellet count with #4