New Member Marble shooter

[jeroentune]

Hello fellow pressure triggers ..

I am new here and i have still tons of material to read and discover but i just wanted to say hello,

My goal is to built a sniper look alike marble shooter .. a single shot version with a top load system .
I want to use a aluminium barrel with a wall thickness of 2 mm . i want to cover it with a carbonfiber tube for looks and reinforcement, I want to add a scope and a laser dot. I am thinking of a 1000cc botlle under the barrel.
I use to work with wood and carbon fibre in other hobbys so i can mold a grip and the boddy work,.
I am still in the dark with the trigger technique but i have seen a electronic trigger valve i like a lot but i am not sure if that will work in high PSI pressure.
i like to shoot targets at 150 foot distance and i need to find out how many psi i need to get my 16mm marble there .
I hope some of you would like to point me a the right direction.

Please " fire " away gentlemen..

[jackssmirkingrevenge]

Welcome!

I am still in the dark with the trigger technique but i have seen a electronic trigger valve i like a lot but i am not sure if that will work in high PSI pressure.

What sort of high pressure do you mean? 10 bar is plenty for shooting marbles at 150 feet.

Do you want to get multiple shots per tank fill? What is your budget?

[jeroentune]

Hello Jack ,

thank you for your answer . 10 bar would be great . i can pump that easy and if that is a save figure i can work with that .
It would be great if i could get 6 ore 7 shots out of 1 tank.

I like to use a 20 OZ tank for my sniper ..allthough a 12OZ bottle would fit and look much better. but i am not sure if that is enough . I like to use a train horn valve , they are strong enough until 250 PSI max and its electric .. i like that ..
I am still not sure what caliber i schoose .. i like the big marbles but there are 11 mm Marbles as well and they should do fine .. I might be able to shoot the AAA battery as well. at this point i am a real newbie. . so i am in the dark considering the caliber.
but i want to do some damage . i like to shoot some holes in wood etc etc .
Budget ... ? i am not in a hurry .. so i can buy every part and built it part after part .

hope that someone can shoot me in the right direction.

[jeroentune]

I just did a new search and i think i want to use the 3/8 caliber slingshot ammo .. this a 9.5mm diameter ammo. can i use a 10 mm Barrel with this ammo ? will that work >?

[jackssmirkingrevenge]

i think i want to use the 3/8 caliber slingshot ammo .. this a 9.5mm diameter ammo. can i use a 10 mm Barrel with this ammo ?

If you want accuracy, you should match the barrel inner diameter as closely as possible to the projectile diameter, and that 0.5mm difference appears small but is significant.

I like to use a 20 OZ tank for my sniper ..although a 12OZ bottle would fit and look much better. but i am not sure if that is enough .

If you can find a decent regulator it should not be a problem, as long as you don't plan to operate in cold temperatures - CO2 drops to about half its pressure at 10 degrees Celsius.

I like to use a train horn valve , they are strong enough until 250 PSI max and its electric .. i like that ..

It won't work, I tried :-/ air horn solenoids tend to "fart" air out at a rapid pulse rate as opposed to blowing it out unobstructed like a sprinkler valve.

Here is a simulation of what performance you would get at 10 bar with a 60cm long barrel, you'd get just over 25 joules of energy and decent velocity, good enough for 150 feet.

Here's a ballistic calculation, look at those numbers and decide whether that is enough performance:

At 50 yards, bullet drop from 35 yards is about 15 inches, and energy drops from 19 ft lbs at the muzzle to 9 ft lbs - still significant but less than half than at point blank range.

[jeroentune]

Hello Jack ,

Thank you for your response and help !
the 8/10/12 mm sizes tube are in Europe easy to find , the USA sizes are more difficult to get . i believe the 10 mm will be realy close to the 3/8 inch ammo i have in mind .. i think this will give me a better cleaerance than a 12mm barrel with a 11 mm marble. if you consider the Milimeter sizes barrel i can use , can you suggest a better combination Barrel/ ammo ?

anything with a barrel of 80 CM ore 32/ 34 inch lenght will be fine. I will try to work with a 12OZ Bottle to start with ..
I can use a QEV and use the Solenoids to trigger ?

thank you for the software workout ! i believe i might pump a little more pressure and move up to 15 ore 18 Bar. i think tis wil effect the curve a bit ..
I wil download the software and try to understand what i am doing .


for the barrel .. i was thinking of a 10mm barrel ID and OD of 13 mm . than a second tube with an ID of 13 mm and a OD of 16mm . i can work out a silencer and will make a loading mechanism with the 16mm tube.. than i will add a 3th layer of 16mm ID Carbon with a 20mm OD .this will also cover the loading mechanism and make it more "airtight " i will add a second tube of carbn with 34 mm for the silencer. i will also drill a small hole in the 10mm barrel and add a small high power magnet so the 3/8 ammo steel balls will stay in place . Does this make sense ?



I have experience with carbon and i can epoxy a gun grip and rails for the scoop.

Hope to hear and learn form you soon

Jerome

[jackssmirkingrevenge]

the 8/10/12 mm sizes tube are in Europe easy to find , the USA sizes are more difficult to get

Don't I know it... but look around eBay and similar, it's not that hard to find corresponding pipe.

You can for example use 12mm pipe and buy 12mm ball bearings as ammunition - the bigger caliber is a better idea if you want to do some damage

can you suggest a better combination Barrel/ ammo ?

Assuming you're in the Netherlands, is it possible for you to get hold of black powder type barrels and bullets? That would give you the ultimate in accuracy and the ability to use lead projectiles that are more dense and therefore keep their power better than steel.

Found a link, not sure if it's helpful: http://www.schietsport.com/dutchmuzzlel ... /SUPPLIERS

anything with a barrel of 80 CM ore 32/ 34 inch lenght will be fine. I will try to work with a 12OZ Bottle to start with ..

Longer barrel is always better for more power and less noise

I can use a QEV and use the Solenoids to trigger ?

Sure, but if you are using CO2 then you will definitely need a regulator to take the pressure down, something like what palmer provides. A solenoid that will be able to take the pressure of unregulated CO2 will be far too expensive.

thank you for the software workout ! i believe i might pump a little more pressure and move up to 15 ore 18 Bar. i think tis wil effect the curve a bit ..
I wil download the software and try to understand what i am doing

.

Double the pressure, double the power, simple as that the software is GGDT, an excellent tool that is worth mastering.

I used this online calculator for external ballistics.

I suggest you have a look at QDV mechanisms:

http://www.spudfiles.com/pneumatic-cann ... 21703.html

http://www.spudfiles.com/pneumatic-cann ... 25131.html

A very efficient valve type that would be able to take the pressure of unregulated CO2 cheaply and would give you tons of performance at low pressure. Here's a simulation with a 12mm bearing, you'd have the muzzle energy of a .22LR rimfire rifle...

[jeroentune]

He Jack ,

thank you again for your compete answer.. most of what you say makes sense to me ,, some of it i must dive in and do my homework .. 10 ore 12 mm is not an issue for me .. hey lets go for 12 mm ..
I can work with that ! I have no idea how to reach 55 bar though .. ! i am hoping to pump 11 with my high quality bike pump . and i have a fork pump that will go until 30 bar .. but thats it ..

I think i will just have to strat somewhere and i will work out my plan with 12mm Ammo. as soon as i have the barrel all worked out i need to design an airflow idea.. including the QEV and a way to control this valve .. i will check the dutch site and see what more info i can find ..

Thank you Jack !!

[jackssmirkingrevenge]

I can work with that ! I have no idea how to reach 55 bar though .. ! i am hoping to pump 11 with my high quality bike pump . and i have a fork pump that will go until 30 bar .. but thats it ..

Ah, I assumed when you said 12oz that you were going to run it on CO2! If you're pumping yourself then 11 bar is just fine and you don't need a regulator, through you will be pumping it for every shot.

Thank you Jack !!

Pleasure, I'm trying to be more attentive to newcomers' questions to keep the spirit of the forum alive

[jeroentune]

Jack, you did understood me very well .. i want to work with a CO2 bottle.. not sure if i will use a 12OZ ore a 20 OZ bottle .. so i think i do need a regulator . I need to draw a scetch with the air flow so i can understand a bit better where to use what part and why !

right now i am in doubt if i would go for a steel a copper ore aluminium inner barrel .. i will cover the barrel with a second layer of aluminuim and a third layer of carbon fiber. . but there must be benefits of coper /steel ore aluminuim as an inner layer .

Thanx again and i will keep this alive . i will make a building post of my air project.

Jeroen

[Brian the brain]

Sorry guys..

Heej Jeroen,

Een QEV heet in het Nederlands een snelontluchter, je vindt ze het goedkoopst op http://www.mattech.nl

Helaas hebben ze geen foto bij het type dat wij gebruiken, heb wel een artikelnummer : 50002121

[jackssmirkingrevenge]

Sorry guys..

I assume you're explaining to Jeroen where he can recover his stolen bicycle

[Brian the brain]

We have forgiven the Germans years ago....

[jeroentune]

Thank you Jack .. I have my bikes locked up safely ..

Brain thanx for the heads up .. I will draw up a scheme of airflow to get the picture even better and design some kind of loading mechanism .. I am also still in doubt about the barrel and the thicknes of the barrel ..

Brian .. do you have a shooting range where you go ? ore just backjard ?

Jeroen

[jackssmirkingrevenge]

Thank you Jack .. I have my bikes locked up safely ..

I see that you learnt your lesson

I apologize for being culturally insensitive, all I know about the Netherlands is stolen bicycles, tulips, windmills, weed and gooooold