Too specific and similar to the spear. I know you don't want to use a spear because that's not what it is, but use a spear.
Alright, I'll take that as a 'no'.
Thanks for your awesome help with the Morion Helmet, though, you've been a great help on this project, see you around. (You will be given credit for your help on the General Discussion Page for my server (when it comes out) and on the server itself. I'd love it if you could drop by once the servers done, also.
I would try to model it but you guys know how bad I am at modelling :I
Maybe I could give you some advice? (I suck at modelling too, but I'm just going to give a basic overview of the weapon to maybe help you a bit.)
I think this picture bests sums up what I'm looking for:

Now look carefully while I'll try to explain the weapons shape and structure.
Now you see that the projectile is mostly made up of a single cylinder, at the middle. But then, as we go further down it cuts off and there is another cylinder; a smaller one, that goes on for a little bit until we come to the flint point at the end. Now, going the other way the large cylinder keeps going, and then comes into contact with some feathers, like on an arrow, and then continues it's cylinder.
The part that is actually touching the man's hand is the Atlatl which is not really needed, anyway. Just the Tlacochtli, the part I just described to you, is what is really needed.
I'm also going to make some adjustments here and to the op on the damage of the Tlacochtli, I've decided a two-hit kill is what I really want for this weapon. I'm changing OP a bit now.
Edit: Shoot! Wrong picture! xD I'll fix that now...
Double-Edit: Picture is fixed.