I (sort of) has full auto :D

Building or modifying BB, Airsoft, and Pellet type of guns. Show off your custom designs, find tips and other discussion. Target practice only!
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jackssmirkingrevenge
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Mon Jan 12, 2009 2:35 am

Spudinator had posted this launcher - sadly the pics are dead - using shotgun slugs shaped like airgun pellets where the ammunition is stacked vertically in a tube magazine and the same concept applies, the round closest to the barrel gets swung forward and is fired while the rest are pushed up the magazine.

Certainly worth looking into, though I'll try a few single shots to see what the power would be like before making anything.

edit: put a few single shots (barrel hooked up directly to the pop-off valve without the blow forward breech) and got an average of 240 feet per second for 1 gram lead pellets and 360 feet per second for 0.25 gram airsoft BBs. It's not that bad in terms of power, in the sense that it would make a very decent skirmishing project, and at 2 ft/lbs with lead pellets would make a reasonable plinker, but I'm looking for a bit MOAR POWER! - so on to the pop-off piloted piston valve it is :)
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Brian the brain
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Mon Jan 12, 2009 4:46 pm

That's awesome I likey. (cool deathray!)
That name is already taken..

Some cool progress you have made Jack!
As I have experienced in my snapvalve /modded QEv set up, low flow tends to give off higher rof.Too much flow and it won't cycle.( wait...the 1/2"QEV did...the 1/4"I tried later gor blown open by the incoming 900 psi)

Turn up the spring tension and you will use up tremendous amounts of air...

The system works but finetuning is a bitch.
It drove me mad that I could not get a better power/rof ratio so I went back to the original bbmg thing..

A micro Uzi style gun is in the works right now.

I flipped ( and cut up) the pressure washer valve and use the 12 gram adapter as the handle ( well in a cover..)

about as compact as it can be, enabling me to harvest the most a 12 gram has to offer..

I might have to incorperate your idea later on...just to see what happens...
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Lentamentalisk
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Mon Jan 12, 2009 8:17 pm

Not to hijack, but BtB, you should leave the CO2 without cover, so that the warmth of your hand can keep up the vapor pressure, as you rapidly boil it. Of course that would come at the cost of frozen hands, but still, its worth it for better performance. You might also want to use some thermal paste to hook up a radiator or something like that to it.
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jackssmirkingrevenge
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Tue Jan 13, 2009 12:12 am

Thanks Brian, to be honest I wasn't so sure about this after your experiences with the snap valve, but you know me, I'd try anything once. It cerainly has potential as an idea, bot not for doing serious damage at shop compressor levels.
A micro Uzi style gun is in the works right now
I have a CO<sub>2</sub> tyre inflator on the way so expect a similar project from me ;)
I might have to incorperate your idea later on...just to see what happens...
One idea I definitely would like to incorporate is this one, it would hopefully make things more economical and cinrease power in the process.
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Brian the brain
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Tue Jan 13, 2009 10:45 am

use some thermal paste to hook up a radiator or something like that to it
You understand I want to build a micro Uzi like gun?

Why would I be carrying around a radiator then?
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Lentamentalisk
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Tue Jan 13, 2009 10:53 am

Well I don't mean a full on radiator, I just mean some copper, or something, to help increase the surface area a little to make it warm up quicker. I suppose with a micro Uzi you want it as small as physically possible, so just forgoing the whole radiator idea and holding on to the CO2 cart with your hands is the best you could do. I just remember how crazily CO2 fluctuates with temperature, so its important to keep it warm.
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jackssmirkingrevenge
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Tue Jan 13, 2009 11:53 am

I would think that insulation is a better idea, it would have to be in your hands for a while to heat up. Another idea is to keep the 12 grams in your pocket before using them ;)

I remember seeing CO<sub>2</sub> tanks for model aircraft motors that had a water jacket for this purpose.
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