Airsoft "grenade launcher" spring

Here is a grenade launcher like spring system for airsoft. Please note that I didn't print it yet so I can't give you any estimation of it's range (could go from 3meters to 30meters), moreover it depends of the hop-up you will give it.

So it's able to shoot 15 BBs per shot thanks to 3 barrels with 5 BBs each. The rubbers are usefull for 2 things : they avoid BBs to get out of the barrel without shooting and they give a hop-up effect for a better range. The model's length is 17 cm.

What you'll need to mount it :

- 1 classic AEG spring
- 1 wire that you will put on the security and the trigger of 2mm diameter
- 3 drilling screws (from 20mm to 40mm)
- an elastic that will be used to make the 3 rubbers
- 2 screws and nuts to mount it on you replica
- some glue for the rubbers and the aestetic cover

First put the spring in the body.
Put the spring pusher on the spring.
Push the spring pusher down and screw the chamber head in the 3 holes.
Mount the trigger by putting you