Just another copper gun

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
Nwest82
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Tue Dec 22, 2009 8:17 am

jackssmirkingrevenge wrote:
Nwest82 wrote:could I get away with a shorter barrel & smaller chamber, scale it down to large pistol sizes and still have high muzzle velocities in .25cal or .38cal/?
It depends how much pressure you are capable of generating. Without the benefit of a long barrel, high pressure is essential for good performance especially in smaller calibres, and you also get the disadvantage of a disproportionally loud shot (unless you like that sort of thing ;) )
Thats what I figured, since in Co2 airguns, (IE: the Crosman 2240), a longer barrel will give more power and utilize the co2 a bit better and a shorter barrel will give less power with a louder *bang* because of that Co2 being wasted at the muzzle.
I'm just guessing but It shouldn't be too hard to get a .25cal bullet shooting at 500-700fps with a 10" barrel and 700-1000fps with a 14" barrel, right? especially if I made it Co2 powered.

Thanks guys, I will likly need help when I start this build :wink:
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jackssmirkingrevenge
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Wed Dec 23, 2009 1:52 am

Nwest82 wrote:I'm just guessing but It shouldn't be too hard to get a .25cal bullet shooting at 500-700fps with a 10" barrel and 700-1000fps with a 14" barrel, right? especially if I made it Co2 powered.
With a fast valve 500-700 fps is certainly possible (assuming a 31 grain pellet) though I would recommend high pressure air over CO<sub>2</sub>, as the latter is a denser gas it will yield less power per unit pressure.

I think Brian's repeater would be a good place to start looking for inspiration, especially if you're after a mutli shot launcher. It will be a challenging first build though, you might want to think about something a little lower spec as a first project.
hectmarr wrote:You have to make many weapons, because this field is long and short life
Nwest82
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Fri Dec 25, 2009 8:03 am

jackssmirkingrevenge wrote:
Nwest82 wrote:I'm just guessing but It shouldn't be too hard to get a .25cal bullet shooting at 500-700fps with a 10" barrel and 700-1000fps with a 14" barrel, right? especially if I made it Co2 powered.
With a fast valve 500-700 fps is certainly possible (assuming a 31 grain pellet) though I would recommend high pressure air over CO<sub>2</sub>, as the latter is a denser gas it will yield less power per unit pressure.

I think Brian's repeater would be a good place to start looking for inspiration, especially if you're after a mutli shot launcher. It will be a challenging first build though, you might want to think about something a little lower spec as a first project.
Well, I'm not new to building just new to launchers, I usually build powderburners. I'll check out that link and see what is possible for me and my tools, Thanks :wink:
bikingpro911
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Tue Jan 05, 2010 9:24 pm

:/ i want a fridge compressor lol. how much pressure does it put out? 200psi? an how do i make one anyway?
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Jeeperforlife
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Tue Jan 05, 2010 10:54 pm

bikingpro911 wrote::/ i want a fridge compressor lol. how much pressure does it put out? 200psi? an how do i make one anyway?
I am not the type to shout about these things but did you even think of searching? This has been covered more times than I can count. Try the search button at the top and don't forget the wiki. HPA is not something that should be spoon fed. You need real knowledge and understanding of what you are doing for safety sake.

Marcus

P.S. My fridge pump puts out over 600 PSI.
Nwest82
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Fri Jan 22, 2010 2:21 am

Jeeperforlife wrote:
bikingpro911 wrote::/ i want a fridge compressor lol. how much pressure does it put out? 200psi? an how do i make one anyway?
I am not the type to shout about these things but did you even think of searching? This has been covered more times than I can count. Try the search button at the top and don't forget the wiki. HPA is not something that should be spoon fed. You need real knowledge and understanding of what you are doing for safety sake.

Marcus

P.S. My fridge pump puts out over 600 PSI.
yeah, i started searching and I'm learning a bunch more than asking questions people can only cover the same topic so many times, eh?
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