This is a re-upload from my first (failed) attempt of a Tec 9 K'nex model. Pretty much the same principles of building as the last one, but this time we now have 3 pieces to modify in order for the design to work.
Step 1: The Body
This is how to build the body of the gun. Just follow the pictures and you won't have any problems. This is as simple as I can make it.
Step 2: The Barrel
This next part becomes more of a trick than what it started but you'll get the idea.
Step 3: The Trigger & Trigger Gaurd
From this point on, everything else with the model is short and simple to build.