This instructable is on how to make a home made BB gun out of very commonly available parts, i have spent ages researching and developing this design to make a cool Christmas present for someone.

I was in the progress of making a home made paintball gun, but the practicalities of it were just stupid. So with a little modification i made a much better BB gun!

Warning: This thing is VERY powerful even with a moderate pressure of 50PSI.

Step 1: Make the gun/barrel

First of all you're going to have to find a garden spraygun with a removable head set up, preferably it must have the trigger in front and be able to release air pressure very rapidly.

Amazingly i found a PVC component that screws exactly onto the spraygun.

The next component is a piece of 21.5mm PVC pipe with a garden hose quick connect thing glue inside.

The alu tube of 6mm or close as possible internal diameter (the closer the more powerful) friction fits with a piece of sticky tape inside of the quick connector.

The length of the barrel has a big effect, the longer the more accurate your BB will travel but at a risk of slowing it down over the length and the shorter it is the faster it will travel withing reason.
<a rel="nofollow" href="http://wilstar.com/midi/shooteye.wav">You'll shoot your eye out, kid!</a><br/>
You can buy a knife at most any store... OMGWTFBBQ YOU STAB YOU EYES OUT! Seriously, stop freaking out about safety.
no kidding high pressure is serious stuff, it might seem like a load of hot air but even a slight weakness in the materials can spell devastating consequences for the user (maybe the plastic would blow up and take part of your face with it).
Yescsafety goggles seem appropriate. <br>
you must have never hurt yourself, therefore you think saftey is not important
or died that suck it hurt lol hmmm...3..2...1...yeah you got it
i watch a christmas story every year
Me to.
I also watch a christmas story every year !!<br>
lols<br />
necro<br />
Your obvious reference to "A Christmas Story" is lost on these fools, I fear...
okkkkk ttthhhheeeennnn..... lol
Looks cool, but exactly how powerful is it?
What's a PET drink bottle?<br>
Any large drinks bottle, pet stands for Polyethylene terephthalate, the material they are made from
Y do u need so many connection and different pieces/......<br /> could u make it so it looks more like a rifle or something<br />
&nbsp;Best ammo ever is called &quot;Piano Wire&quot; It's like metal stiff wire that can pierce wood (?) but will definitely pierce thin wood.
Nice idea dude nice
Where did you get the hose sprayer thing?
it looks so small in the picture
check out my instructable its simmiliar
hmm. i think the thing about a shorter barrel being slower may not actually be true. It depends on the situation, but on Mythbusters they made an 80 foot barrel to try and propel straw thru a tree.
yeah but in mythbusters, the barrel was bigger than the projectile, and air did not push the straw, a cotton ball was pushed, and that pushed a straw, its different with nerf guns and stuff where the projectile fits snuggly in the barrel and the air pressure eventually equals and the bullet is still halfway down the barrel, then gets stuck.
What is mythbusters?
a tv shows on discovery channel
one thing you missed was on mythbusters they used a long barrel to increase accuracy and to increase momentum .
In firearms, generally the longer the barrel, the higher the pressure, and muzzle velocity. Comparing muzzle velocities of a 2", 4" & 6" barrel of the same model will always show this. Same holds true for velocities from a .357 carbine compared to a .357 pistol. There is undoubtedly a point where you COULD get diminishing returns from a longer barrel, theoretically, but I don't think it's encountered in normal barrel lengths in normal firearms. However, with the far lower chamber pressures and muzzle velocities in these air-driven devices, I can believe you might lost velocity with a longer barrel, ESPECIALLY if the fit between the BB and the inside of the barrel were a bit sloppy. In firearms, you will recall, the fit is extremely tight, thereby holding pressure all the way down the barrel.
mount it on a rifle cut frome wood and add a pump with a spring so it open the valve to charge the mini tank. the only proplem would be adding a a mag
High pressure and tape don't exactly add up so I dont't think that any sort of tape should be used in any stage of the construction of this gun. It could result in injury or it could reduce the effeciency of the gun.
wraping one or both bottles in ducttape would be a cheep, eficent and light way to reenforce the bottles. id still use only 150 PSI though. airsoft is made of plastic or ruber and would slow down or even stop in the barrel if it was not lubercated. brass shot would work best.
Hi, I like the idea and also think you could use DRY ICE to pressure up to 500-800psi "in a metal tank". It would would need a regulator of some kind.
i thought about that but dismissed the idea because of having to refill it after it ran out of dry ice and that that stuff is fairly dangerous in the wrong hands
and youll need armour of some kind. youre practically re-inventing the pressurized-air hand fragmentation grenade. itd work, but itd sure be heavy
While this is a really clever design, and a very well-done project, I have to agree that this could be really dangerous, and I'd personally never want to handle it. I've seena lot of plastics fail under pressure, especially in cold weather or after sunlight (UV, I guess) had degraded the material -- PVC & CPVC, especially. And I've used a lot of the quick-release plastic fittings around the farm. Sometimes you get lucky, but most of them have failed eventually, often with very messy results. I still use them occasionally (only with usual water pressure, never with a booster), and only until I can get a brass fitting to replace it. I know it would drive up the cost considerably, but doing this strictly with metal parts, no plastic, is the only truly safe way to do this. It just ain't worth the risk of having a bit of fractured plastic blasting into your eyeball. Or genitalia. Not to be a wet blanket, but there's a reason things like SCUBA tanks, oxygen tanks, etc., are carefully tested & certified. Pressure can hurt or kill you, with a bit of bad luck, and we should keep this in mind when we fiddle about.
hunting weapon!<br/>illegal around here =(<br/>
lame :/ things like this should be legal.
um will this puncture cardboard? with airsoft?
sorry for double posting but a very handy adapter for the bottle is a truck valve (part that goes into the rim) the stay in quite tight anyway so get cheap superglue and coat it in that to slide it in then use a good strong epoxy glue for assurance
experiences of water bottle rockets etc have withstood pressures of 120PSI that was a coke bottle but 500Ml bottles are even stronger pressure wise also a we built a similar item at 250 PSI out of a random bit of pipe with the perfect diameter but the most fearsome weapon was heavy gauge hosepipe with marbles down it, add a needle valve and 200 psi but about half the marble flew out till a mishapen one got stuck and the hosepipe burst....
Would a little water and dry ice in the larger tank mean you could fire BBs longer without refilling the tank? That could be a "portable" pressurization system.
dry ice is too dangerous for use with a plastic bottle (do a video search for "dry ice bomb") If you use dry ice, only do it with a metal container that has a pressure relief valve on it.
"uh oh, its jammed." *blows arm off*
Cool i made one with a few of my twists, like an autoloader, and i enjoy going airsofting with it.
now that is cool
were did you find this piece of crap
pretty dammm sweet but do u know how to make it faster to reload instead of pumping up the tank if you find out a way please tell me
hi cool BB gun design it is simular to my pump air blowgun with the same trigger design keep up the good work, you should look at my instructables
<em>I was in the progress of making a home made paintball gun, but the practicalities of it were just stupid. So with a little modification i made a much better BB gun!</em><br/><br/>so a BB gun is more practical than a paintball gun?<br/>

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