DISCLAIMER: MAKE NO MISTAKE, THIS IS A WEAPON. DO NOT SHOOT AT ANYTHING FRAGIAL OR ANYONE. IF ANY PROBLEM OR DESTRUCTION IS CAUSED BY THIS, I CLAIM NO RESPONSIBILITY.
Step 1: Materials
-Approximately 1.25 meters (4 feet) of 1/2 inch PVC pipe - you probably won't need that much but keep it just in case you mess up on a step.
-A 591 mL soft-drink bottle like what you normally drink coke out of
-A small sports pump
-PVC fittings (all 1/2 inch): 1 ball valve, 1 "T" shaped fitting and 3 elbows
-Hack saw and serrated steak knife
-Hot glue gun
-PVC bonding glue (optional)
I got all my PVC and fittings from a lumber store, not a hardware store. They only sell in 10 foot lengths so it cost me around 7 dollars (Canadian).
Step 2: Preparation
PAY ATTENTION! This part is important
Cut your pieces according to the picture and the descriptions. These are just approximate measurements and you can customize them at will. Numbers indicate the PVC pieces and letters indicate the fittings. The measurements are all in cm. This is the list of pieces used. Make sure that before you cut them that you label them so you know which pieces go where.
1a: T shaped fitting
2a: Ball valve
4a: Elbow fitting
5a: Elbow fitting
6a: Elbow fitting
Mark lines on a long bit of PVC where your individual pieces will be. Then number each piece so that once you have cut them, you don't get them mixed up. To cut your pieces, use a serrated steak knife to make a large grove in the marked line you want to cut. Then once the grove is big enough, use a hacksaw to grind away. Beware, the hacksaw is not a precision tool. Don't be too messy or else your PVC pipe will be all rough. Once you have your pieces, it would be better if you sanded them to be nice and smooth.
Then arrange them in the order in the picture. You can lightly attach the pieces together but don't glue anything together yet.
Remember, use the picture!
Step 3: Gluing
First, apply a small amount of PVC bonding glue to the end of piece 1. Then fit that end into the soft drink bottle. The piece should stick.
Then remove the needle on your sports pump. Stick it inside of piece 7 and glue it.
It is then up to you to glue the rest in the same manner. You can choose not to because it may be useful to replace some parts without having to throw away the whole gun. I recommend to Never glue the two ends of piece 2a (ball valve) because it is the single most expensive piece on the gun and 5 dollars.
Step 4: Making Bullets
The easiest and one of the most effective ones are just rocks with enough masking tape to fit down a barrel.
Aluminum foil is always fun, going faster than a hard bullet but they do not hurt at all. Unfortunately, they are limited with accuracy to only ten meters. Don't be fooled, if one of these hits someone in the eye, they're blind.
The one of the deadliest bullets in the arsenal. Three small nuts (nuts and bolts) taped together with a lot of tape so they fit the barrel tightly.
The classic pouring water down the barrel is so intense. It sprays well and has a lot of recoil!
The greatest and evilest bullet here is hardly a bullet but a dart. Take a nail about 4 cm long and put a ball of foil down until the flat part stops it. Then tape it secure. Make sure it snugly fits in the barrel and also has no trouble going down. Then take some more foil and roll it into a compact tube 3 cm long. Then add some tape fins to one end. These fins are angled apart from each other like a helicopter rotor so that it spins in flight. Attach this tube onto the end of the foil ball.
Step 5: Tips
Just bundle them up with a ton of duct tape.
Also, the ball valve is very stiff. Put a few drops of handyman grease on the valve, (not too much!) and it should be fine.
Also, you can create a ring sight like the one in the picture. If you have any questions or things I could update, post them in the comments.
Due to the screwed up trigger system, I will be posting a new instructable on a very reliable sniper rifle with an extremely smooth trigger that I built already.