This guide written by Connor McCann who runs the
Foam Action Network
The How & The Why
Constructing a Nerf blowgun is incredibly easy. To make a basic blowgun, all you need is a chunk of PVC pipe, a mouthpiece of some sort and other supplies depending on if you're securing the blowgun to another blaster (zip ties/duct tapes) or using it as a stand alone weapon (a sling).
If you're securing the blowgun to another blaster, the blaster you will be using will have to have a flat surface to work with. I recommend using a Stryfe (with a stock extension) or Rampage. This type of blowgun will give an extra advantage for sniper shots in Blaster vs. Blaster (BvB) games such as TacOPS, giving you extra cover fire or a last resort in HvZ when your primary jams or is out of ammo.
As a stand alone weapon, I recommend using a sling that goes around your back, in addition to carrying a primary blaster/multiple sidearms to keep pace with the opposing force when they close the distance with you. You can use a blowgun as your primary, but either stay within a squad/group that will offer you lots of cover fire or be prepared to run like crazy all game.
I recommend using Whistler Darts above all else in terms of ammo. When using a shorter blowgun secured to a blaster, you can get ranges past 75', up to 90'. However, the extra foot of length, combined with Whistler Darts (which are made of thicker foam and have a heavier tip then streamlines), gives the stand alone blowgun consistent ranges of 100'+, with the occasional lucky shot clipping a player at close to 150'.
Its a great weapon for surprise assaults, static defense, complementing an assaulting force and especially when coupled with Whistler Darts, psychological warfare. The whistle alone freaks out enough players that they retreat, regardless of whether anyone has been hit. If you have a couple of heavies close by, they'll easily handle the fleeing enemies. Its an awesome 1-2 punch so I recommend bringing one out to your next Nerf War.