When they get more mature, three or four months old, the males get a longer snood and a bigger dewlap, and tend to have sturdier leg bones and bigger feet too. I find that if I look down on the top of their heads of the younger ones, sometimes the toms are wider across the skull from ear to ear, behind the eyes, and from the font, they are thicker behind the jaws, or there is more spread to the jaw bones and the u-shaped bone that goes up and down in their throat when they breathe. I have only had a few turkeys so don't take my word for it.
The toms heads tend to much redder when they are young. If you have a large ton they will all crowd around him trying to pick fights. The hens are smaller. The tome snoods start getting larger. Once they are mature they will of course gobble. Pictures would help.
It depends on what age the turkeys are. As 2 day old Pulets, turkeys can be vent sexed if you know how, I believe BB bronze and Great white can be feathered sexed.
Most of us have wait until they get older about 2 to 3 months old. There is no 100 percent accurate method except to cut them open and look at there sex organs. But usually most turkey will have sex characteristics.
Snoods: Males will be long and hang down most of the time, but they can draw them up, But the base of the snood will be large. Female will be small and won't dangle down. Females usually don't change size much.
Carnuckles: The bumps on there necks, males will have more and they are usually more red, when excited.
Head strip: Usually there is strip of small feathers on the turkeys head. for females it's more pronounced then males.
Gobble: usually females don't gobble, a noise that is different then what they are use to can make a turkey goggle, Like banging two pieces of metal together. or a cell phone ringing.
Size: If you have males and females the males will be larger.
Face color: Females usually have more bluish color then red, when they are excited. But I have seen males and females so close you can't tell. Generally the snood will lengthen when they get excited and change face color.
Usually the size and shape of the snood is the easiest way to get a clue if they are male or female when they are younger. But with this years batch of Spanish Blacks we have all the males draw up the snoods when I get close, so I have to watch for how big the base of the snood is.
Also it much easier if you have both sexes present, and you can't always rely on on sex characteristic to tell.