Quote from one of Joe's latest posts sort of lets out those bigger shot sizes, now doesn't it.
I'd try 2's but they are illegal in most states I hunt.
I know not where all Joe hunts, but do note he is from TN & happen to know that TN law specifies shot no larger than #4 for turkey hunting.
I also note that at least early enough to be included in his 1910 book, W W Greener stated the only advantage a 10 "Bore" held over a 12 "Bore" was with shot loads exceeding 1¼ oz. He recommended a load of 4 drams 1½oz for most useage.