How reliable is this method for sexing corns?

I know this probably isn't an exact way to tell a male from a female,(as I was told) but has anyone had any luck using the tail shape of a snake to tell if it is male or female? I have one about 2 foot long who is supposed to be a male but the tail tapers immediately at the vent, and from the vent to the tip of the tail is only 4 inches, so I am wondering if I got a female instead of a male.
I am hinking about if it is 3 feet long next spring, putting it in with my male snow and seeing if they try to mate. Would they try to kill each other if both are males?

thinking, not hinking! lol Can't spell tonight.

Putting two corn snakes together in an attempt to determine their sex doesn't really work too well. Two males may start 'strutting' around (is it possible to do that without legs?!?...lol) even if there is no female present. Even if you do put a male and female together, they won't necessarily 'notice' each other right away. If you are trying to visually sex your corn snake, this image might help. I stole the pic from Kathy Love's site... I hope she doesn't mind!!

if you don't have a lot of experience with it, it can be tough to sex corns by just looking. its funny, some snakes i can tell at a glance...others I have to probe (and am sometimes unsure then, lol). I have known people that could accurately sex colubrids by visualization alone. I never worked with them enough to be good at it - I was so hot and cold you might as well have said I was just guessing.

but those pics do make it look pretty easy

You also want to be more concerned with weight then length when breeding the female. Ensure that she is at least 300 grams prior to attempting to breed her; and of good muscle definition.

So it could be a male and look like that?

Sometimes no matter how good you think you can visually sex, you end up getting it wrong almost as many times as you get it right. The best thing to do is to have him/her/it probed for sure.

Originally Posted by reptilebaby

So it could be a male and look like that?

It very well can be. I have a female that no matter how many times I asked the breeder "Are you sure this is a female???" I just would not believe she wasn't a male just because her tail base was so thick. She probed female every time. Some just break all visual rules.

For me, looking at the tail from the side and checking the taper from tail base to the tail's midpoint works better than looking at the tail from the underside. The snakes are less likely to freak out if they aren't turned upside down, too. YMMV.

In my opinion, visual sexing is up to 90% accurate, and probing is up to 95% accurate. Experience increases accuracy with every method, of course.