I would suggest ATLEAST a 20 gauge 3 in shell. Most people use 12 gauge 3" or 3.5" shell, and I know that some use 10 gauges as well. Don't know of anyone who has ever shot a turkey with a 410. Are you asking if turkey are as big as quail or the turkeys head? I knew someone who killed a turkey with 7 1/2 shot but I wouldn't even recommend that. Hope this helps. Maybe someone can prove me wrong, but I wouldn't think a 410 would be sufficient to get a good clean kill.