Today Im going to show you possibly the easiest and most effective way to make a air soft machine gun, and surprisingly enough, it will only cost you 3$ or even less if you have your supplies on hand. This rapid fire pistol is capable of shooting up to 15 rounds per second and has a effective range of 50 ft. And even better, it requires no co2 pr batteries and you can refill its air tank in battle. In addition to all of this, the SMG can shoot up to 100 continuous bbs at 100-200fps on a full tank of air. So if your up to it and want to make your own air soft guns instead of spending 25$ for a useless spring pistol or 150$ for an actually SMG, then lets get to work.

Step 1: Supplies

Like i said, it is possible that you could already have these supplies on hand, since there is only 3 parts. You will need:
- a pressure sprayer(normally used for gardening, you can get one for 2-3$ at the dollar store)
- a soda bottle(or any bottle really)
- and a emptied bic pen, airsoft barrel, or 7mm brakeline( any tube that can fit bbs, i used the barrel from a old air soft gun)

Step 2: Making Holes

First off, take the bottle and carve or drill hole in the back of it big enough for the spout of the pressure sprayer to fit in. Next drill a hole in the cap of the bottle big enough for your barrel to fit in. This is the only drilling you will need to do.

Step 3: Constructing

Now, with a hot glue gun or any type of glue or epoxy, put the barrel through the hole you made in the cap of the bottle. glue the barrel in place. Then take the pressure sprayer and place its spout inside the hole you made in the back of the bottle, glue this in place. Your gun should look like pic. 1 in the end. If your glue jobs are air tight, then your done from here.

Step 4: To Shoot

Like many diy airsoft guns, this gun has the cloud mechanism, meaning that high pressure air enters the reservoir(bottle) through one opening and leaves the reservoir in another opening, and since there is only one opening where air can escape, bbs inside the reservoir are blown around until they meet up with the opening and exit the reservoir at high speeds.
To shoot this airsoft gun you must first fill the bottle halfway with bbs and then pump up the pressure sprayer. Once you have a reasonable amount of pressure in the sprayer, you can press the air release trigger on the handle and bbs will shoot out of the gun.
As always when using airsoft guns, wear eye protection.