"Scew Action" Firearms

[Axt]

Heres a couple guns which ive dubbed "screw action", very simple & versatile.

This is the gun I made reference to in the gun turret thread, though I lost the original so I made it again.

<img src="http://ww1.ft100.com/~45653/guns.ft100.com/images/pengun.jpg" alt=" - " />

It uses a couple "olive pressure fittings?" joined in a coupling? (ive no idea what the actual fittings names are) originaly made to fire a dart via a shotshell primer, but as the dart is destroyed every shot you can load a #7.5 shot into the 1/8" brass barrel (about .10cal) for quite a high velocity. The dart works quite well and is very quiet as the barrel volume more then doubles before the dart leaves the muzzle.

<a href="http://ww1.ft100.com/~45653/guns.ft100.com/images/pengundiagram.jpg" target="_blank">Diagram</a>
<a href="http://ww1.ft100.com/~45653/guns.ft100.com/images/pengunbreak.jpg" target="_blank">Parts</a>
<a href="http://miss.fnpsites.com/pengunshoot.avi" target="_blank">test avi</a> &lt;-- LINKS DOWN

This one is a 12ga handgun, never fired from my hand as I dont truly trust the ergonomics of it in regards to recoil.

<img src="http://ww1.ft100.com/~45653/guns.ft100.com/images/12ga.jpg" alt=" - " />

The 12ga itself using a load of shot I think would only be lethal to about 2 or 3 metres. A 1oz slug is the round of choice.

Its nice as (in theory) you could screw any sized barrel onto it in any calibre as long as its a rimmed case. Ive seen the 20mm pipe (used in the barrel) with ID's down to 9mm. and if you use the shotshell to provide the propellant even up to <a href="http://ww1.ft100.com/~45653/guns.ft100.com/images/grenadelauncher.jpg" target="_blank">40mm</a> :)

<small>[ March 17, 2003, 01:48 AM: Message edited by: Axt ]</small>

[Mr Cool]

The dart gun is very neat - have you done any penetration tests?
Do you use wadding behind the projectile?

Edit: what exactly is happening in the video? It isn't very clear...

<small>[ February 24, 2003, 07:48 AM: Message edited by: Mr Cool ]</small>

[Observer]

Looks like the dart goes through the wooden board, then the bottle. Bubbles enter the bottle after the projectile has passed as the water starts to pour out.
Nice construction by the way.

[Axt]

Does the movie work? did for me at home but it isnt for me now..

Not sure what the movie is but its the .10cal ball shooting through either a aerosol can or a plank & 1.25L coke bottle of water, in either case it went right through.

If the movie is the one with the plank, the fins get stuck in the wood, it doesnt penetrate as far as the lead ball, which I think is supersonic, though its a lot smaller and a lot louder.

For the wadding I guess you mean with the .10cal ball, it doesnt need it as after the first shot there is enough residue in the barrel to hold it in place.

edit: Observer has noted what movie it is, but its the lead ball not the dart, and water didnt actually pour out until the bottle had 10 (very small) holes in it.

<small>[ February 24, 2003, 08:31 AM: Message edited by: Axt ]</small>

[dave]

Great gun, sort of reminds me of my gun. Your gun uses pipe to make, i was just wondering what schedule is that pipe and has it ever failed on you?

[Ezekiel Kane]

Thats a great idea man. It reminds me of the scene in Phantasm where the boy tapes a shotgun shell onto a hammer and swings it into the door, blowing a six inch hole in it. Anyway, you might consider designing the tip to release a poison held in the dart upon impact. I'm not sure how much work that would require, though. Just an idea.

[Axt]

There is a number of pipe sizes in the barrel, to provide the right sized chamber/barrel.

We dont use the "schedule" system in Australia, though I have heard talk of it so there may be direct equivalents. Ours is sold as light/medium/heavy/extra heavy etc.. in seamless/seamed. 20mm is same as 3/4" (about 26mm OD) and 25mm is 1" (I think around 32mm OD) based on the BSP thread sizes.

<img src="http://ww1.ft100.com/~45653/guns.ft100.com/images/12gabarrel.gif" alt=" - " />

I made it as strong as I could with what was on hand, the pipe is unlikely to fail, the weld at the back of the fitting is probably the weakest part which there has been no problems with.

Poison would not be too easy with this design as the dart fits over the barrel as opposed to inside it, so must be hollow.

<small>[ February 24, 2003, 08:22 PM: Message edited by: Axt ]</small>

[Charlie Workman]

Nice piece of work, Axt. It's always good to see someones ideas in action. You've basically reinvented the "Airrow" gun which is manufactured in the US. It uses the same tube down the center of the dart (or crossbow bolt in their case). It uses common .22 blanks to launch the bolt at about 450 feet per second. Noise is said to be about half of that of a conventional .22. If you're interested in finding out more, do a websearch on "airrow". Keep up the good work, you've given me some ideas to play with on my own.

[smokey]

nothing like a bit of good old aussie lateral designing its a nea idea, thanx for sharing it with us

(Nothing like a worth-while post, either :p ~MrC)

<small>[ March 07, 2003, 02:01 PM: Message edited by: Mr Cool ]</small>

[Axt]

Did you search for " <a href="http://www.swivelmachine.com/html/rimfire.htm" target="_blank">airrow</a>" not "airarrow" ...

It seems to give a surprisingly high velocity to the arrow, considering its weight and the "dead air space" between the charge and arrow. You could probably increase the velocity by adding wadding to a wire runnig up inside the arrow to remove the air space, though you would get more noise/pressure.

Heres some misc. construction pics I took while making it, was going to make a site but im pretty bloody lazy.

firing pin
<img src="http://ww1.ft100.com/~45653/guns.ft100.com/images/firingpin.jpg" alt=" - " />

opposing faces
<img src="http://ww1.ft100.com/~45653/guns.ft100.com/images/faces.jpg" alt=" - " />

working parts
<img src="http://ww1.ft100.com/~45653/guns.ft100.com/images/pengunbreak2.jpg" alt=" - " />

To avoid confusion the thing at the back of the dart in pic (first post) is a small rifle primer (probably where the wadding question came from is it?), dont bother with anything less then shotshell primers as I did try small rifle/large rifle/large pistol/shotshell, with shotshell by far the best with no pressure problems.

The holes to accomodate the primers were -
small rifle - 4.5mm
large rifle/pistol - 5.5mm
shotshell - 6.5mm (6mm is a tight fit, hard to get back out)

A 2mm drill bit firing pin is right size for shotshell primers and perfect fit inside the 1/8" fitting, so fits together easy with little work needed.

<small>[ March 07, 2003, 11:50 PM: Message edited by: Axt ]</small>

[Mr Cool]

</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica">probably where the wadding question came from is it?</font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">My wadding question came from my confusion, I didn't understand how it worked fully. I didn't realise that the pipe went inside the arrow, so I was wondering what stopped the gases from just rushing past it. But now it is clear.

[smokey]

thanks axt, i did spell it wrong ( i can be a dumbass somtimes )
i have seen a similar rifle to the airow a long time ago it was used for harpooning small whales , it consiste of a 303 with nothing forward of the magazine exept the barell with everthing turned of so that it was just a smooth tube a hollow spear about 3 foot long with a mean motherfukin barbed head on it and a loop to attach a line to it i never saw it fired though i would think that it would only be used over 10 - 50 metres

[Bigfoot]

Just in case anyone's wondering, I believe "olive fittings" are known as compression fittings in the US. A look at the compression rings will tell you why the nick "olive".

Why not reverse the bolt? Then, using a wingnu, you'd have a safety of sorts.

<small>[ March 11, 2003, 10:46 AM: Message edited by: Bigfoot ]</small>

[Fukineh]

This is very interesting as just a few days ago I (before reading this) started experimenting with my own zip guns and I am almost finished making one out of brass fittings like yours. The main difference is, my gun uses C7 assault rifle and C9 light machine gun blanks as a charge and I load home made ammunition in front of the blanks. Where do I get these in Canada? My friend is in the army, and he can easily jack blank ammunition. He could jack live ammunition and grenades if he really wanted to, but if he where caught.......

Anyway, I am very pleased with the power displayed by a crude prototype (it shot a small screw through a wooden cabinet). Since my friends role in the army is a C6 gunner (heavy machine gun), I would eventually like to construct one of these to shoot C6 rounds. I don't know how safe and effective that would be in a handgun, however, so we would probably have to make that one a rifle.

[zaibatsu]

Heavy machine gunner? So we're talking large calibre, .308&lt;, pressures created by those rounds will be large. Plus, you'll have to cut a chamber using a chamber reamer as they are bottle-necked and not straight wall cartridges. Plus, to make any use of the large powder charge you'll need a long barrel. In short, I'm doubtful, but it'd be great if you could, and if you do - post pics <img border="0" title="" alt="[Wink]" src="wink.gif" />

[Fukineh]

Don't worry, I won't be taking any chances with C6 ammunition (7.62 mm rounds). That's just a long term plan for now.

BTW Axt; I would love to see how you did the trigger configuration on your hand gun. I need to have a fireing pin that does not obstruct loading my gun (it loads from the back, and the pin hole is in the screw on end cap which gets taken off to reload.)

<small>[ March 12, 2003, 11:29 PM: Message edited by: Fukineh ]</small>

[BoB-]

I'm also curious, is the 12gauge pistol firing mechanism just like the dart guns'?

[Axt]

The wingnut safety isnt a bad idea, as is the "hammer" always sits on the firing pin, a couple turns just to pull it off would make it safer, though could also become a bit of a pain.

Yes the trigger mech. is nearly the same for both.

<img src="http://ww1.ft100.com/~45653/guns.ft100.com/images/12gatrigger.jpg" alt=" - " />

[Fukineh]

Thanks for the diagrams. What I'm probably going to end up doing with my gun is to have the chamber and barrel on a hinge that can bend down while I load, then fold back up to the firing pin system after it has been loaded.

So are you using just the primers to fire darts/pellets? If so, how much power to you get? I may try making a tiny pocket sized primer gun if it acually provides adaquite power. One could even make it more or less semi auto if they attatched the pellets to the primers first and made a magazine. This could also be accomplished with .22 rounds, which strangely enough, I dont have access to; I can only get hold of high caliber amunition easily.

<small>[ March 16, 2003, 02:00 PM: Message edited by: Fukineh ]</small>

[Axt]

Yes, its just the shotshell primer. If you managed to get the movie before it went down you would have seen what it could do.

I remember once in a shooting magazine there was someone loading .22cal pellets over shotshell primers in a 22 hornet case. If I remember right the velocity was around 650fps, though I think the pellet would have been decellerating before it got to the muzzle in a rifle.

As you could imagine, a primer forms a very fast propellant therefor quite well suited to short barrels firing light, small calibre rounds.

[Fukineh]

Sounds cool; is there any way that you could try re-linking to video?

[Axt]

No, I dont have the movie anymore, and I wont make it back home for a couple months to make another.

[Fukineh]

Guess I will just have to try it for myself then. I just got hold of some .22 shells, so I'm also going to make a prototype for them. I'm hoping that if I make something small (pocket sized) the charge won't be overly wasted, then again, with rifle ammunition in a handgun you aren't usually going to get great efficiency.

I'm currently working on the handle and trigger for my C7 blank ammunition gun, and when it's done I may post some pictures.

<small>[ March 17, 2003, 06:32 PM: Message edited by: Fukineh ]</small>