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Preview: Semi-Automatic Pneumatic Pistol

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#1 PVC Arsenal 17

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Posted 18 August 2009 - 10:05 PM

First post here. I'm a regular at SpudFiles.com. I've been building all sorts of pneumatic stuff for years. Here's something I've been working on recently, nearly finished.

Posted Image

Posted Image

I don't have much time right now to post up a description but I'll come around tomorrow with some more pictures and videos of the thing in action. Just a couple more parts to build and this thing is done.
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#2 stuck by stefan

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Posted 18 August 2009 - 10:24 PM

This is a nerf forum.
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This is the NerfHaven profile of Northeast Designs. For more info visit https://www.facebook...p8OwIso&fref=nf

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#3 PVC Arsenal 17

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Posted 18 August 2009 - 10:28 PM

This is a Nerf gun. :P Semi automatic, shelled.
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#4 SonReeceSonJensen

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Posted 18 August 2009 - 10:52 PM

I checked out Spudfiles: holy mother f is some of that stuff intense.

Welcome to the haven, Iím not sure what shooting a 1 lb potato 300 yards translates into for a micro Stephen but I canít wait to see.
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The Difference:
-Guns shoot bullets that kill people
-Blasters shoot darts that tag people

I do not play with guns.

#5 Echnalaid

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Posted 18 August 2009 - 11:26 PM

I checked out Spudfiles: holy mother f is some of that stuff intense.

Welcome to the haven, Iím not sure what shooting a 1 lb potato 300 yards translates into for a micro Stephen but I canít wait to see.

A hole in your glasses and head where your eyeball was supposed to be.
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#6 PVC Arsenal 17

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Posted 18 August 2009 - 11:55 PM

I checked out Spudfiles: holy mother f is some of that stuff intense.

Welcome to the haven, Iím not sure what shooting a 1 lb potato 300 yards translates into for a micro Stephen but I canít wait to see.

A hole in your glasses and head where your eyeball was supposed to be.


@SonReeceSonJensen: Thanks for the welcome

@Echnalaid: Incorrect. It is a common misconception that pneumatic = dangerous. That's largely in part due to the things the spudgun world has produced, but raw power is not always the goal. Unfortunately many people do not realize this. My blaster was designed with safety in mind. The operating pressure is completely adjustable, meaning I can regulate the dart's velocity to that of an unmodified toy Nerf gun, or less if I choose.



While I'm at it I'll post some quick details.

Power Source: Compressed air (HPA) or CO2 (both regulated)
Operating Pressure Range: 1-300psi
Estimated Operating Pressure: 75psi (that's a very rough guess, I'll need to run comparisons alongside a toy blaster to determine this for safety reasons)
Ammo: 1/2" x 2" homemade Nerf darts

The darts are preloaded into "shells" (Tubes that act as protection for the darts so they may enter the blaster properly. Each "shell" essentially serves as an individual barrel for each dart, though supplemental barrels may be added.)

After firing, the empty shell is ejected and a loaded one enters the gun from a magazine (not shown). This process repeats with every pull of the trigger, true semi-auto.


Tomorrow I'll get to work building a few magazines with various capacities. I'll need to find the balance between capacity and compactness so the gun is most effective during Humans Vs. Zombies (This blaster was built specifically for the game). I also need to come up with some kind of simple retaining system for the magazines.

I added a simple removable stock using a slightly modified Nylon quick disconnect air fitting. Without the stock, the size of the blaster is comparable to a Nite Finder as shown. With the stock, the length is slightly longer than a Firefly. Of course the length of the stock can be changed to fit the shooter's needs.


Most of the construction is PVC. (For anyone concerned, all pressurized parts are either brass or steel, all are more than capable of handling pressures far greater than what I will be subjecting them to.) When held, there are no creaks and no play in any parts. The blaster feels quite solid. It was built to handle a great deal of abuse from typical gameplay.

More later.
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#7 Dr BoB

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Posted 19 August 2009 - 01:20 AM

So your saying you pull the trigger it shoots, ejects the shell, then reloads from a clip. How fast is this process? How much did this cost? Also, what kind of ranges does that thing get at certain levels of psi?
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QUOTE(Goombadude3 @ Oct 5 2009, 07:34 PM) View Post
The awkward cocker is a big down side

Yes it is indeed.

#8 pjotrkuh

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Posted 19 August 2009 - 06:58 AM

So your saying you pull the trigger it shoots, ejects the shell, then reloads from a clip. How fast is this process? How much did this cost? Also, what kind of ranges does that thing get at certain levels of psi?


Errr.... You only watch pictures dont you? or did you completly miss the bottom sentence in the first post?


Either way, PVC Arsenal 17, what function is the cylinder thing on the side of the gun?
And nice work on machening the handle, but it looks a little to "straight"
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#9 PVC Arsenal 17

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Posted 19 August 2009 - 06:40 PM

I ran out of music wire so I'll have to save the magazines for a different day. I need music wire to make box springs.

I did do some rough tests while holding the shell in place by hand. At about 50psi, it's shooting at close to the speed of a modified nerf gun. I took it to 200psi just for fun... Lost that dart. I'm happy with the range of speeds I am able achieve by adjusting the pressure since safety is a major concern.


@Dr. Bob: Yes, that is how it works. The pneumatics are capable of cycling at rates much higher than I'm able to accomplish by pulling the trigger on my own. Provided the magazine can feed fast enough and no jams are encountered, I expect the gun to fire as fast as I can pull the trigger. That's somewhere in the realm of 10 shots per second.

I need to iron out some of the kinks with the ejection port to ensure that the empty shells drop out consistently, but then I should be good to go. It may be necessary to add some sort of detents to keep the shells in place until the gun ejects them. I have some small torsion springs that should do the job.


@pjotrkuh: The cylinder does a couple things. First, it serves as the chamber volume for the gun. The gas inside the cylinder fires the dart when you pull the trigger. Second, the cylinder moves to actuate a simple mechanism that kicks the empty shell out of the gun.

I considered making some kind of molded grip custom fit to my hand but for simplicty's sake I went with a bare minimum grip. It was most important that the grip was strong, and it came out very strong.

Edited by PVC Arsenal 17, 19 August 2009 - 06:46 PM.

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#10 TantumBull

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Posted 19 August 2009 - 07:05 PM

First off, let me say this: very, very nice job. That thing is sleek, compact and effective all at once. That's a real nice blaster you have there.

There's just one thing about it that sort of bugs me, that being it requires a pre-pressurized tank to function, meaning you're not actually priming it while nerfing. To keep the playing field level, in most cases, the blaster needs to be primed during the round. The reason for this rule is to prevent exactly this, which is playing paintball with foam projectiles. Basically what I'm saying is that this blaster would be too effective on the playing field. Anything using a secondary, pre-pressurized tank has the potential to be way unfair, and not even nerf anymore.

But otherwise, it looks real nice and sounds like it functions nice as well. I would just consider this as more of an experimental project than a blaster that should be used in an actual war.
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#11 rbtying

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Posted 19 August 2009 - 07:53 PM

Do people consider Captain Slug's backpack tank war-legal? Because it seems like it'd be about equivalent as we could get to a prepressurized LPA tank, like the one the TFS uses.
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#12 elf avec gun

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Posted 19 August 2009 - 09:06 PM

Do people consider Captain Slug's backpack tank war-legal? Because it seems like it'd be about equivalent as we could get to a prepressurized LPA tank, like the one the TFS uses.



That is different because it requires the user to wear a large cumbersome cylinder on their back.
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#13 Blacksunshine

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Posted 19 August 2009 - 09:18 PM

This would be the equivalent to a modified paintball blaster if turned up. If it can be regulated then it could be war feasible. The general range of most highly modified that are war acceptable are 100-120ft. So if you were to dial it in around there it might actually be actually use it in a war. Anything higher and you would be looking at a safety and fairness issues. But I must say very nice work. how much has all this setup set you back?
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#14 rbtying

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Posted 20 August 2009 - 01:15 AM

I really, really want to see this in action. Is it just me, or are an abnormally large number of legitimate semi-auto homemades being built?
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#15 jackster57

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Posted 20 August 2009 - 03:29 PM

What is the trigger valve? Where was it purchased?
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#16 Bedhed117

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Posted 20 August 2009 - 07:44 PM

There's just one thing about it that sort of bugs me, that being it requires a pre-pressurized tank to function, meaning you're not actually priming it while nerfing. To keep the playing field level, in most cases, the blaster needs to be primed during the round. The reason for this rule is to prevent exactly this, which is playing paintball with foam projectiles. Basically what I'm saying is that this blaster would be too effective on the playing field. Anything using a secondary, pre-pressurized tank has the potential to be way unfair, and not even nerf anymore.


First off nice work. I love the fact that its adjustable. I'm a kind nerfer so all my guns (even the singled titan) are modded to hit forty flat. This gun looks like it can do the same thing. Also I love semi-autos. I like the handle being flat, it looks less likely to break. The overall look of it reminds me of the trank guns that the government used in that tv show on NBC where people have superpowers. I just have a few questions

1) How do you change the PSI?
2)How big is the magazine?
3)How many shots can you get off of one of those CO2 tanks?
4)Is a writeup on the way.
5)(Already asked) How much does it cost to make.
6)Is there any glue on it or is it all held together with screws?

Tantum- Just because it kicks ass doesn't mean its unfair. If it fires like a real firearm or airsoft gun it doesn't mean its not nerf. It stopped being Nerf when people started using homemade darts and guns. Nerf is a brand of toy guns. This is not a toy.
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QUOTE(Bedhed117 @ Aug 18 2009, 09:48 AM)

Anyone who's sig is a quote of themselves is an enormous douchebag.

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#17 TantumBull

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Posted 20 August 2009 - 08:43 PM

If it fires like a real firearm or airsoft gun...

That pretty much ruined your argument. Take this to PM's from here if you really care enough to respond. I don't want to clog PVC's thread with this crap, which has been over-discussed.

Edit in response to below posts:
Let me start out by saying that I enjoy nerfing because of how nerfing actually takes place on the at a war. I like nerfing because you don't have guns that have the ability to keep people pinned behind cover for long periods of time, you don't have a blaster that you can just spray and pray with. Nerf unlike airsoft and PB, doesn't require a bunch of cover to be fun. When you need a bunch of cover it seriously limits your venues for a war. Now that you understand why I enjoy nerf, maybe you will see why I'm against semi-auto blasters that can shoot ridiculously far.

When you first start integrating these types of blasters into the playing field at wars, there are going to be some problems. Namely that the kid who comes with a stock nightfinder isn't going to have much fun. Now don't get me wrong, you don't have to do well to have fun with nerfing, but getting dominated all day by someone with some crazy set-up isn't much fun either.

And when and it gets to the point where everyone has access to these kinds of blasters, there's when this hobby becomes really unattractive to me. If you don't understand why then read the first paragraph. I don't want nerf to be the new paintball or airsoft. And it definitely will get to that point. Look at how far mods and everything have come in the past 8 or 9 years.

Also, the reason me and many others are against tanks with pre-pressurized air tanks is that it gives you too many ways to make a gun that will cause others to not enjoy the sport. But I do think that making stuff like this is really cool. I'll be getting started on a semi-auto bb gun at some point soon here, and will most likely PM the OP from this thread for some help on that. But that isn't nerf.

Edited by TantumBull, 20 August 2009 - 10:10 PM.

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#18 Blacksunshine

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Posted 20 August 2009 - 09:19 PM

There is no rule about having to prime a blaster. the reason you don't see semi autos at a war is because people cant make them. him having the ablity to rapidly shoot darts simply means he is going to be out of darts sooner.
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#19 xtremejumpy

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Posted 20 August 2009 - 09:33 PM

Well, a Semi with beast range is great! You guys say has to be primed and crap like that, but he has to still load the shells/magazine then load them into the gun. He probably shoots them off faster than he can reload.

I freaking love the thing. So pretty. *sigh* I wish I had a girl- I mean gun like that. Although a girl that could blow that hard...
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#20 PVC Arsenal 17

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Posted 20 August 2009 - 09:47 PM

The magazines will be put on hold until my shipment of polycarbonate sheet comes in. (The mags are made from polycarbonate) I got my music wire today and I was all excited about putting a few mags together, but it turns out my polycarbonate is too thin so I've ordered a thicker sheet. Proper feeding requires that the magazine walls completely fill the gap between the magazine receiver and the breech opening. The sheet I have now doesn't do that so there's an obstruction.

Now I'll answer your questions:
1) The pressure is adjusted by turning a screw on the top of my Palmer's Low Pressure CO2 Regulator.
2) The magazine size has not been determined.
3) I don't know how many shots I can get from a 20oz CO2 tank but I suppose I could find out... I don't feel like it at the moment :D
4) A writeup is certainly on the way.

5) This project has been in the works since last August. I tried many designs before this one, some worked, some didn't, but either way I wasn't satisfied until I came up with this design. (It's completely my own, btw) Between all the previous prototypes and the parts and tools necessary to build them, I've spent well over $650. All the parts that went into what you see here plus the co2 system cost significantly less, however. If I had to guess, maybe $200, probably more.

6) Details of the construction will be posted with the writeup.


@TantumBull: I think what Bedhed117 meant with his firearm comment is that the TFS operates semi-automatically and ejects shells like the real thing. In fact, I think he makes a valid point about the definition of a Nerf gun and how it's lost it's meaning these days.

In any case, that discussion should probably take place over PM. Whether or not the TFS is fair really doesn't matter, it will never see a Nerf war. As I said before, it was build for and will be used for Humans Vs. Zombies. The playing field is never even in that game, especially not the way my friends and I play.
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#21 Bedhed117

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Posted 20 August 2009 - 11:01 PM

A writeup is certainly on the way.

Hooray! :D

If I had to guess, maybe $200, probably more.

Crap. :D

Oh well the +bow is expensive too.
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QUOTE(Bedhed117 @ Aug 18 2009, 09:48 AM)

Anyone who's sig is a quote of themselves is an enormous douchebag.

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#22 Doom

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Posted 21 August 2009 - 06:17 AM

PVC Arsenal 17, it's about time you showed up here! (I know some people would say the same about me too...)

I have a pretty good idea of what's going on based on what you've posted at Spudfiles and through our own correspondence. Having not seen the progress until now I will say that it's looking very nice. You should check out this gun for some magazine retaining system ideas. The spring-pin combination he used is very simple.

Also, what sort of ranges are you getting? If you're getting anything respectable I might seriously consider "upgrading/downgrading" (depending on how you look at it) to the smaller class of QEVs that you're using. This is one reason I've been delaying the FANG project.

Edit: I'm btrettel at SpudFiles if you don't know.

Edited by Doom, 23 August 2009 - 07:26 PM.

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#23 PVC Arsenal 17

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Posted 21 August 2009 - 11:58 AM

Good to hear from you, Ben! Thanks for the compliments.

The magazine retaining system on the VOS-Pistol is very clever. It's simple enough to make. Hopefully I have room between the mag receiver and the trigger to fit it. I will definitely consider it.

This design is fairly new, I put it all together within the past week or so. The design I mentioned earlier this summer that had nearly 3" of dead space was abandoned. I settled on this one when I got my JEV-F2F2 and found that I could fit the whole thing inside the gun. I'm still unsure about the whole dead space issue, but now there is only 1/8" of it.

Originally I intended to put the cylinder perpendicular to the gun and have its rod eject the shell directly. I decided to put it parallel to the gun for a more streamlined configuration and found that by doing so, I could cut the chamber volume to the bare minimum. It now consists of only the cylinder and the 1/8" nipple connecting it to the QEV. I can't really reduce it anymore than that without doing away with the semi-auto aspect, so I'm satisfied with how it is.

I can't say much yet about the ranges I can achieve with the JEV-F2F2 but I can easily outshoot modded nerf guns at fairly low pressures. I need to do some proper tests with a magazine and better darts, I've made only horrible ones so far.

For now, here's a video of the gun firing and ejecting one shot. Without the mag, I had to hold the shell in place. I did not push it out by hand, however.
Posted Image

Edited by PVC Arsenal 17, 21 August 2009 - 12:00 PM.

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#24 pjotrkuh

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Posted 21 August 2009 - 12:10 PM

Video ain't working......
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When the shit hits the fan, you'd better wear a rain coat.....

#25 rbtying

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Posted 21 August 2009 - 12:11 PM

Video's not working for me.
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