Simple copper coax

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.
whoa044
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Sat Jun 15, 2013 2:39 pm

It's a fairly light gun, compared to the barrel sealer I have (in the background of the second pic). It's not as powerful though, so it's just for backyard plinking.
Lead balls fly a little too slowly with this gun for my liking, so I'm also looking for some lighter ammo that I could use, and maybe with the 54->50 cal sabots I have. Any ideas?
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wyz2285
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Sat Jun 15, 2013 2:59 pm

Used a MB03 stock?
Ever thought of a scope mount rather than the tape?
I'm more interested in the gun in the back of the second photo, a ball valve piloted piston valve? The chamber configuration is very similar to something I've made in the early days :)
CpTn_lAw wrote: :D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
whoa044
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Sat Jun 15, 2013 3:36 pm

You got the stock right. I have a picatinny rail but I decided against mounting it since the tape is good enough for me. I'm doing any shooting past 50yds.

I'll post some pics of the other gun. It's actually piloted by a quick disconnect
whoa044
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Sat Jun 15, 2013 3:41 pm

At 250psi this sends a 12.5 gram lead ball at ~490fps

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The index finger goes into the loop
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The steel pipe chamber makes this gun heavy. I'm considering replacing it with a copper chamber.
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wyz2285
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Sat Jun 15, 2013 3:51 pm

Nice usage of that slide valve! (I assume that's what you mean by quick connect)
If you piston valve is good enough, the current setup sure give you semi auto(dry fire.semi auto, as you don't have a automated reloading system yet), but looking good there!
EDIT
My mistake, it is a quick connection. Then I'd suggest replace it by a slide valve (any DCV would work), and reduce the pilot volume.
CpTn_lAw wrote: :D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
whoa044
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Sat Jun 15, 2013 4:40 pm

The piston has a great seal, but I kinda like the power behind a one-shot system, despite it being a long process to fire.

I was thinking of carrying around a paintball tank and having a regulator supply the gun with air, which will remove all the time spent filling it with a bike pump.

I haven't figured something out for the loading system yet. As of now I have to unscrew the barrel and load it from the back every time
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wyz2285
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Sat Jun 15, 2013 4:50 pm

Take a good look through the pneumatic showcase and the how to data base, you'll be amused.
CpTn_lAw wrote: :D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
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jackssmirkingrevenge
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Sun Jun 16, 2013 12:08 am

Shame it has some little ghetto features constrasting with an otherwise good build.
It's not as powerful though, so it's just for backyard plinking.


What pressure are you running at?

What do your pistons look like?
hectmarr wrote:You have to make many weapons, because this field is long and short life
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dart guy
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Mon Jun 17, 2013 10:17 am

just an idea for ammo try using a sabot with a full core like take a 22 lead slug and encase it in wax
whoa044
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Mon Jun 17, 2013 10:59 am

250psi is the highest my pump will go and most shots are around 220.
When I take the gun apart I'll take a picture of the piston and weigh it. It's solid delrin, about 1.5" long and 1.2" in diameter.
The piston travels about 0.3"-0.5".
I'm thinking the power issue comes from the small chamber.

I haven't tried wax yet, but im curious to know if it will leave any buildup in the barrel
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jackssmirkingrevenge
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Tue Jun 18, 2013 1:40 am

whoa044 wrote:250psi is the highest my pump will go and most shots are around 220.
When I take the gun apart I'll take a picture of the piston and weigh it. It's solid delrin, about 1.5" long and 1.2" in diameter.
The piston travels about 0.3"-0.5".
I'm thinking the power issue comes from the small chamber.
With that pressure and chamber size, power should not be an issue. I'm more inclined to think that your piston is a little loose (or the copper pipe it's riding in is not perfectly round...) and maybe can afford to slim down a little.
hectmarr wrote:You have to make many weapons, because this field is long and short life
whoa044
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Wed Jun 19, 2013 11:58 am

Ironically this gun's valve has the best seal out of any other one I've made.

I think I'm just a little demanding with power haha
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