Okay, it's not that much of a mod, but rather a different method of shooting. Oh well. My Sniper Mode for Joemonkey's automatic airsoft blowgun will moderately increase it's range and power(which means more pain.)
Step 1: Take the Magazine Out.
It's not that hard.
Step 2: Loading
Drop the pellet in to the hole. Put your finger on it so that you are both keeping the pellet from moving and sealing the air in. Blow in to the blowgun. If you did it right, the pellet should not move and air should come out the front. Yep.
Step 3: Fire!
Take a deep breath and blow as hard as you can. When you are half way through the breath lift your finger a little bit so that the pellet can fly out. It should shoot 10-20 feet. Happy sniping!