LOL. These posts! Okay. Let me clear some stuff up.
Not only that, but Tranq Gun is more canon than Nikita in the sense it was the far more frequently used weapon in MGS, as well as the more appropriate one.
And the way that it works is that it will put anyone who is hit and on the ground, into sleep. If you're in the air, it just kinda hits you like a shiek needle. The gun as 3 shots, before Snake has to reload. You can reload prematurely and top off your mag.