20 ga vs 12 ga for Turkeys?

[Crash]

I know that 12 ga 3 1/2" magnum shells give a substantial range advantage over 20 ga 3" shells, but how about 12 ga 3" vs 20 ga 3" shells? The 12s carry more shot at a slightly higher (100 fps) velocity, but is it really that much of an advantage?

Crash

[Jusme]

Probably not a velocity issue, but more pellets means more pellets on target. JMHO

[puma guy]

Probably not a velocity issue, but more pellets means more pellets on target. JMHO

Shot shells vary in the weight of the shot charge. You can buy a 12ga shell with a 1 oz loading and a 20ga with the same load. The number of identical size shot pellets in a 1 oz load will be the same in a 12 or a 20. Will both a 12ga and a 20ga with similar choke have the same number of pellets in the standard 30 in circle (ie shot density) at 30 yards? Theoretically they could, but in reality you'll have do the test in your shotgun for real performance. I'm not a shotgun turkey hunter, but it seems most of them go for min 3" or 3-1/2" 12ga and max shot load. They seem to be going for max shot loading with extra full chokes. I don't know if that's marketing or reality. Is there a particular reason you'd prefer a 20ga over a 12ga? Bob Brister the father of Sporting Clays in America wrote a very good book titled "Shotgunning: The Art and the Science". You can get them on Ebay for less than 10 bucks if you have patience. Worth reading if you like shotguns. In it he points out that at close range, choke for choke a .410 has a larger pattern spread than a 12ga. I have only taken turkeys with a rifle. I keep a scoped Marlin 39 Mountie in my stand while deer hunting. I shot one with a .270 once. It wasn't as bad as you imagine, it was a large tom and very close, so I aimed for the base of the neck.