ihaveguitarskills! says: Feb 18, 2013. 3:26 PM

In the US, you don't need a 'gun license', because it doesn't exist. You need a 200$ tax stamp, and a Class III/II Weapons License to buy a silencer.

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bighead5454 says: Dec 31, 2011. 6:30 PM

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?

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de0509 in reply to bighead5454Jan 13, 2012. 7:24 PM

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

ihaveguitarskills! in reply to de0509Feb 18, 2013. 3:23 PM

For everything that has a barrel, there is a 'perfect length'. Where its at the point where its most efficient. If the barrel is too long it will lose momentum because the gas or air is expanding, but too short and it wont expand enough.

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bighead5454 in reply to de0509Jan 22, 2012. 7:37 PM

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).

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stevenh429 says: Nov 1, 2011. 5:43 AM

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?

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ihaveguitarskills! in reply to stevenh429Feb 27, 2012. 7:09 PM

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

ihaveguitarskills! in reply to ihaveguitarskills!Feb 18, 2013. 3:21 PM

I never remember reading this ible, and I was browsing the comments and found mine XD

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AudioMaximus says: Nov 21, 2011. 5:48 PM

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.

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LiquidLightning says: Aug 8, 2011. 7:12 PM

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".

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syco kid says: Feb 8, 2011. 10:54 PM

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

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LiquidLightning in reply to syco kidAug 8, 2011. 7:09 PM

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

B00GYman says: Apr 30, 2011. 1:15 AM

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

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Electroinnovation in reply to B00GYmanJun 16, 2011. 7:15 AM

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.

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apples!!!!! says: May 12, 2011. 3:10 PM

I watched that video.

Do I bloody like apples? That pained me.

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

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cloveless says: Mar 27, 2011. 3:38 PM

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

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PKTraceur says: Jan 18, 2009. 6:36 AM

NG audio portal rocks!

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blugyblug in reply to PKTraceurJan 19, 2009. 10:50 PM

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

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ElvenChild in reply to blugyblugMar 14, 2011. 9:33 AM

I prefer the kriotube and the piano translations made by fans

saukmulti says: Feb 27, 2011. 2:42 AM

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

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cohlms says: Feb 25, 2011. 11:06 AM

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

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dinu555 says: Dec 19, 2010. 6:51 AM

GUYS I GOT A DOUBT

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

CAN ANY1 CLARIFY ME

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wardog says: Oct 14, 2010. 9:09 PM

Can i use marbles as my ammo? :DD

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awaite says: Sep 29, 2010. 9:21 AM

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

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Thomas Crowe says: Jul 16, 2010. 5:14 AM

Not everywhere! Murder is illegal...lol!

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brum says: Jun 28, 2010. 9:43 PM

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.

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brum in reply to brumJun 28, 2010. 9:51 PM

This project cost me approximately $80AU

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brum in reply to brumJun 30, 2010. 5:13 AM

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 says: Apr 6, 2010. 2:41 PM

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

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brain in a jar in reply to VulcanatorJun 1, 2010. 12:40 AM

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.

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bombmaker2 in reply to VulcanatorMay 1, 2010. 10:15 AM

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

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brum says: May 25, 2010. 4:00 AM

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)?

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thelastonekills says: Mar 26, 2010. 11:44 PM

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

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bombmaker2 says: Mar 25, 2010. 4:31 PM

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.

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messmaker says: Mar 21, 2010. 5:41 AM

Aussies rule =D

Not many of us on here blugy =]

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2bigbros says: Feb 12, 2010. 7:59 PM

i made it and it looks awesome!!!!!! excepted im making mine for paintballs

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knuckel says: Feb 7, 2010. 6:26 PM

Mine does like the same stuff except from like 150 feet away

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igaara says: Feb 5, 2010. 5:25 AM

im new to this so i wanted to know how to pump the air in the gun. Is it through the air tube from the tire? Any help is greatly appreciated.

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bowmaster says: Jan 22, 2010. 7:18 PM

*cough*blowgundarts*cough*

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fede casagrande says: Jan 14, 2010. 7:55 PM

Did you realy think we nead more weapons to play with???

Realmente pensas que necesitamos mas armas con las que jugar???
a Qué?

desde SudAmerica.

F-

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