A 15mm Beginner / Intermediate Pneumatic Sniper Rifle

New video added.
Haha, I remember making this gun 2 years ago. Was bored and I randomly found my own instructable on a google search. (Yeah it still works even though this thing is 2 years old).
Alright... This cannon is pneumatically powered, fired by a modified 25mm Sprinkler Valve. It is a typical spud cannon that lots of people have probably seen before. The chamber acts as a stock and handle at the same time, and 1 side of binoculars for the scope.(and I find no problem with pressurizing the stock because if a chamber explodes... your stuffed whichever way you put it)

I call this gun an "Beginners'" cannon because really, a sprinkler valve is for beginners and intermediate spud gunners. Ball Valve Pneumatics are for Newbies. I don't mean that as an insult, because really, my first cannon was a ball valver. Sprinkler Valves are the "Next step up". If you are building this as your first cannon-Don't. Make a Ball Valve pneumatic or a basic combustion. They are really simple and will let you understand all that darned physics and forces etc etc unless you're alot older than me, and you already know all that stuff.
The video

It is an over-under design, by the way which means that the chamber is underneath the barrel or other way around.

NOTE: I take no responsibility in any harm/damage/death you do with this WEAPON. This is not a little marsh mellow thing for 5 year olds that shoots 2 metres. If used dangerously or as a weapon, it could kill someone with the right ammo. Only make this if you are at least 10 years old, or if you have a good common sense.
NEW PAINTING STEP COMING SOON
This is my first instructable, and I'm only 12 years old. So don't be mean

AND BEFORE YOU ASK STUPID QUESTIONS LIKE "HOW FAR DOES IT SHOOT" AND "CAN I MAKE THIS AUTOMATIC" Actually do some research first.

Step 1 What you'll need (Lol Hi brandon, hi alex lin)

Yep. What you gotta have. I have made a list of what you need.

15mm Pipe 1Metre(3ft)*# (AUS$4)
25mm Pipe 1Metre (3ft)*#(AUS$6)
2x 25mm Tee*#($2 each)
2x 25mm 90 degrees Elbow*#($1.50 ea)
2x 25mm 45 degrees Elbow*#($2-3 ea
25-15mm Threaded Reducer Bushing (1 end threaded)*(I bought a 25-20mm and a 20-15mm reducer. Both were about AUS$2-3)
2x 25mm Male-Slip Adapter (I forgot what these are called)* ($2-3)
25mm End Cap*($2-3)
25mm Orbit WaterMaster in line automatic sprinkler valve.* (Irrigation or Gardening Section)
OR A 25mm Rainbird in line automatic sprinkler valve CP-100 OR Orbit Jar Top Sprinkler Valve.($25-30)
Blow Gun Valve(?)($3-5)
Air Hose(?)($3-5 per merter)
1/4' Barbed Hose Adapter*#(same size as air hose-$1-2
Tire Valve(?)($2)
PVC Cement*#(Forgot Price
PVC Primer*#(Forgot price)
Drill*
Teflon/PTF Tape.*#(?)
Binoculars (For scope) OPTIONAL
Everything marked with a (*) you should be able to get at a HardWare Store ie (Australia) Bunnings, Mitre 10. (USA) Lowes, HomeDepot. Everything marked with a (#) You should be able to get at a Plumbing Store.
As for the (?) Marked stuff...
You should be able to get Blow Guns at places that sell Air Compressors and Air Compressor Fittings. They are used to blow little specs of dust away. Air hoses you can probably get at the same place.
Tire Valves you can get at any place that sells tires, or repairs cars. Sometimes they give it to you for free. Otherwise go to a junkyard with a knife and cut off the valve from a car tire. Binoculars are easy to find, but use an old one, not one of those obese professional binoculars that zoom 1000x, with adjustable lens.. blah blah
ALL PRICES ARE APPROXIMATE, AND AROUND THE PRICES I GOT THEM FOR. FOR YOU IT MIGHT BE CHEAPER OR MORE EXPENSIVE. DONT BLAME ME. GO SNEEZE A PILLOWCASE

NOTES:
Okay, a male pipe is a pipe that has threads on the OUTSIDE. a female pipe has threads on the INSIDE. An Elbow is simply a bend, a Tee is a bit of pipe that looks like a T. A Nipple is a short length of pipe with two male threads. A Coupling/Coupler has Female threads.
REMEMBER TO GET ALL PIPES PRESSURE RATED THIS IS SO IMPORTANT I CANT STRESS IT ENOUGH. If you get that stupid DWV Foam core stuff it will seriously stuff up your cannon...It will stuff you up even more when (not if) it explodes.

25-15mm Reducer Bushings are kind of rare where i live, it might not be where you are so yeah. Just get a normal 25-25 Bushing or maybe a 25-20mm. Then add some normal Reducer couplings. ie Bushing->Short Pipe->25-20mm Reducer->Short Pipe->20-15mm Reducer->Barrel.

Instead of getting a Hose barb and Air hose, you can attach the Blowgun Valve directly to the Sprinkler Valve with a 1/4' (6mm) Nipple.

Comments

[stevenh429]

If you put a t-angle on the barrel with a length of pipe and add a locking tire chuck with an air-compressor...could you make this semi auto? I am going to make this (my 4th airgun, 3 are ball valvers :D)
p.s. put marbles in the t-angle?

[ihaveguitarskills!]

im going to use co2 instead, and then i can maybe make it semi, or possibly full even. make some marble mags.

[bighead5454]

Would a shorter barrel increase or decrease power? It would provide less friction on the ammo, but also provide less length for the pressure to push the ammo, so which would prevail?

[de0509]

barrel length shouldnt "increase" power. it merely makes the energy more efficient. with a short barrel, the projectile gets out fast and the extra pressure will be ejected as well and just wasted. try measure your pressure in atm. it would roughly indicate how much it would expand. i.e. 2 atm will expand to 2 times the chamber volume.

now V = Ad. and we know that the cross sectional area of the pipes are roughly same. so just use length instead of volume
. i.e. 50 cm pipe for chamber at 3 atm shold expand to 150cm.

chamber length + barrel length = final length of air
50 + X = 150
X = 100
so no use of making the barrel longer than 100 cm.

but remember that friction exists and the air cools off on expansion. so it wouldnt expand to 150 on the dot. so, instead of 100cm barrel, cut off some at the end

hope im not wrong, but hope this could help

[bighead5454]

Thanks for the amazing explanation (that wasn't sarcasm). It helps, and I think is is interesting how even the simplest types of math can be confusing with explanation (I first saw the math, and my jaw dropped, then looked more closely).

[AudioMaximus]

I gotta say that building this as only a 12 year old is quite impressive. Im only 16 and I am on an FRC robotics team (electrical subteam co-leader!) so i work with these kinds of things a lot. nevertheless, i love the fact that younger kids are getting into this kind of stuff. Kudos to u, good sir.

[Xenel]

Most stores that sell any kind of guns also sell scopes. Slap one of those on there and its way better than that binocular crap!

[blugyblug]

Yeah it probably is, but don't you need a gun license to buy one of those? You need a gun license for a silencer you know.

[LiquidLightning]

Nope, no license needed. At least in the US, I remember just walking into big 5 when I was twelve and buying a high power rifle scope, they didn't say a thing except "Thanks come again".

[brum]

Not in Australia mate, im an aussie with a firearm licence and i know u dont need one to buy a scope, however i am quite sure that silencers are illeagal in australia, especially concidering that they have banned hand guns. i am going to make this only a bit more snazzy. Got a scope that i bout ages ago for an air rifle, 12x zoom and also a bolt action so that the ammo doesnt have to be barrel fed. Marbles will be the ammo. Just with the modding of the sprinkler valve i have found one (also know i found as a solenoid valve but even your local plumbing expert may not know what ur on about) the one i have has a plasic diaphram guide pole and now solenoid or flow control (less work) is the best option just drilling next to it and tapping the hole and inserting the adapter? also with the hose that goes to the trigger anything in particular (pressure rated)?

[weasel999]

silensers are ILEGAL

[Thomas Crowe]

Not everywhere! Murder is illegal...lol!

[RMConstruction]

Depends where.

[Xenel]

If that does'nt work you could use one of those air gun scopes which would still be better than binoculars.

[toxicwolf]

you could use the scope from a 22rifle

[blugyblug]

Yeah but...well, airsoft guns are illegal in australia too... But if youre in the US that would be great lols.

[pork_belly108]

Yeah that sucks. I always wanted to handle an airsoft ( mainly because of their looks and removable clip and sliding mechanism, dont care if they shoot or not).

[syco kid]

hey does it have to be a car tube valve or can it be a normal push bike tube valve

[LiquidLightning]

They are usually exactly the same, except that car valves are seperate pieces and bike valves are integral to the inner tube.

[B00GYman]

why is a sprinkerler valve better? what is the advantage?

[Electroinnovation]

Because the way they are designed makes it so it is a lot easier to release all of the air at once, where ball valves depend on user speed. The sprinkler valves allow more air out quicker thus resulting in a faster and more accurate shot. Also, its much less of a pain to squeeze a trigger than to rapidly twist a valve.

[apples!!!!!]

I watched that video.

Do I bloody like apples? That pained me.

...on a more serious note, excellent build.

[cloveless]

Excuse can somebody plzz tell me wat does "over under bit" mean on one of the pvc pipes when u hover your mouse over it???????!!!!!!!.............PLEASE REPLY I WANNA SHOOOT MANY MANY SQUIRELS

[PKTraceur]

NG audio portal rocks!

[blugyblug]

I know! Dimrain47 makes the best techno. My favorite is TT or maybe The Prototype..

[ElvenChild]

I prefer the kriotube and the piano translations made by fans

[saukmulti]

i'm feeling stupid
i don't know if im stoopid
but how many valve does it used??
can u make a video for making them

[cohlms]

does the sprinler valve let all the preasure out at once or is it controllable ?

[woodstockbirdy]

Where is the outlet???

Srry dumb question but I dont know.

[dinu555]

GUYS I GOT A DOUBT

ABOUT HOW WE LOAD OUR AMMO..................


CAN ANY1 CLARIFY ME

[wardog]

Can i use marbles as my ammo? :DD

[awaite]

Do you reckon u could do some small game hunting with this gun like rabbits?

[brum]

Hey can anyone please give me a hand, i have made my gun but even at 85 psi the diaphram wont pop up and let all the pressure through and i dunno y. its not the spring cos i took it out and it made no difference, u said u used 40 psi maybe the rubber is stiffer or the whole in the diaphram is too big just wanna get opinions.

[brum]

This project cost me approximately $80AU

[brum]

Never mind i found that the hole in the diaphragm to let the air through and where the guide rod goes was to big a gap so i filled the sides of the guide rod with hot glue, and um, WOW WHAT A HOME-MADE WEAPON, CRAZY POWERFUL AT 80-85 PSI, HAVEN'T TRIED ABOVE THAT (compressor restrictions) highly recommend these concepts but be creative and come up with a slightly different way of doing it like I did. GOOD LUCK TO ANYONE TRYING THIS! WELL WORTH IT WHEN U GET IT RIGHT...

[Vulcanator]

 Does anyone know of a reliable way/source of cheap ammunition for a 1 inch barrel? other than what was mentioned above..

[brain in a jar]

if you had a 15 mm barrel like my spud rifle, you can get a 4 inch galvanized nail and pit it down the actual center of a nozzle from a hand silicon putty gun thing.
like the ones on the end of liquid nails.

[bombmaker2]

You could use plaster of paris lugs in the barrel. There's an instructable about it somewhere but i can't recall the name.

[thelastonekills]

i made one and nuts and bolts are cool ammo. but ferrite core's with silicon in the middle are fun as hell!!!

[bombmaker2]

I don't know exactly how I'm gonna do it, but once I build an exact replica of the Barret M82A3 .50 caliber sniper I will find a way to fit this gun (with some slight mods) into the case.