--If you don't believe me you can wikipedia "Venturi effect",
Most people are only moding the barrel and spring!!!!!
Step 1: The restrictor
--Start with cutting out the center. Then work you way outwards so that the dart will fit but have slight resistance.
If your going to use a custom barrel the size will vary.
Step 2: Making the Venturi
and blocked in the center.....
Simply cut through the center and try to keep the hole the same size as the front piece. Everyone does this so it's no secret>
I prefer to use Quick Steel to fill the holes of the back piece because it cures fast and it's easy to sand or Dremel when needed.
Step 4: What it should look like
Step 6: Taking out the Spring
--First your going to have to pre-loosen the little tabs on the inside. There's three of them that need to be pry'd back. It's going to smash the orange tip inwards a bit but that's what needs to be done. See Picture.
Here's the link to the Video: