Step 4Upgrading: Last Part
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Last thing to do is to plug up the hole on the bottom of the beginning of the barrel. You'll want to be very careful when you do this. It's right after the orange cylinder, and keeps the pressure inside the dart from getting "out of control." What this thing does it take all your compressed air that your spring just made, and throw half in the trash. Sealing this hole will allow you to throw more air in the dart, applying more force and shooting it faster and farther. This is what will really help you welt your friends.
Do this by using some sort of really good epoxy or silicone gasket maker. First make sure the whole and surrounding surface is clean. Then very carefully, kind of work it in the hole but not through it. If you use too much, it will stop the round from moving. If you use too much on the outside, it won't go back in the cylinder when you pull the bolt back.
Thanks.