Home Artillery (improvised weaponry)

[NoltaiR]

Well an idea that I have had for quite a while just began to take effect today when I actually found a 10 foot length of galvanized steel pipe with threaded ends. The pipe will be cut into two 5 foot test barrels. What is so perfect about the pipe is that it is just barely wide enough to hold a CO2 cartridge... in my previous thoughts I figured I wouldn't be able to find a pipe like this so I was probably going to have to spend some extra time welding and finding peices of scrap metal to use. Anyways I also recieved a 'donation' from a next door neighbor (my old testing side-kick) of two dozen emptied CO2 cartridges. I drew up a quick design about an hour ago but now that I am finally posting this I have noticed that there is an error in my thoughts about placing an 'impact nail' into the CO2 cartridge.

<a href="http://www28.brinkster.com/emcatalouge/save/artil.gif" target="_blank">http://www28.brinkster.com/emcatalouge/save/artil.gif</a>

sorry about the bad quality.. when you are using a combination of MSPAINT '98 and some old gif creating program, you are garanteed to get bad results

[Eliteforum]

Why would you fill a tree with wirewool? The image is hard to read and understand. Install Photoshop!

[NoltaiR]

Sorry about not explaining it better. The idea to this is that the end cap is unscrewed, and the projectile is slid into position (about 1 inch down the pipe. Then a spoonful or so of BP is put in the open inch of the barrel. The end cap has two holes drilled in at angles (less chance of gas escaping around wire leads) and the wires are firmly pulled through. A few strands of steel wool are run between the two leads and the resulting miniature ignition setup is gently pushed into the BP so that some of the strands are buried in the BP and some are not. The end cap is screwed back on slowly but firmly (and yes this will disturb the BP a little but it shouldn't matter) and the whole artillery setup is backed up against a tree for support (in the picture I show a steel plate being first attached to the tree and then the artillery setup is pushed up flush to the plate).

[Liam C.]

How do you intend to reload the firing charge?

It possible that I'm looking at the picture all wrong, but it looks like getting it ready to fire again would be quite time consuming, unless you plan on having pre-made (and pre-wired) pipe caps (is the cap attached to the tree?). Even then it would seem too time consuming for any kind of usable(?) sustained rate of fire. I would think that it would be much faster to weld the cap onto the pipe and tamp in the propellant charge (pre-measured) just like they did back in the old days...

You might want to consider "nesting" the barrel inside another, slightly larger, steel pipe for safety/strength as well...

The CO2 round bothers me though. I've never done any shock tests on AP before but my first thought was... "BOOM in the barrel". Firing the cannon will be quite a shock to the round.

.
Hmmm... sorry it looks redundant Noltair. You posted while I was writing...

<small>[ November 13, 2002, 01:04 AM: Message edited by: Liam C. ]</small>

[0EZ0]

Sounds like a good project :p . You are quite lucky to have found that pipe.

Got a few suggestions for you:

Firstly, there is a reason why artillary shells are not filled with a primary explosive. You don't want the shell prematurely exploding either before leaving the barrel, or before you load it into the barrel while you are still handling it <img border="0" title="" alt="[Wink]" src="wink.gif" /> . Find a Secondary HE that is within your reach of aquiring/manufacturing.

Secondly for your shell casing you mention using a CO₂ cartridge. Sounds fine. To use simply empty the cartridge and the drill out the 'capped end for eventually loading the HE of your choice through it. Later another hole will be drilled for the detonator assembly before the HE filling. For placement of the 'impact detonator' look a little below**..

As for the impact detonator/igniter, one could quite easily create one from a product that is used almost exactly for that purpose, ie. a shotgun shell primer. Just attach one to your choice of detonator, then attach a BB round or similiar to the 'cup' end of the shotgun shell primer to act as the 'hammer'. So that upon impact the BB round strikes the cup end of the primer setting it off.

**Now for placement of the detonator. Assuming you are using the CO₂ cartridge as the shell casing, the impact part of the detonator is going to have to be at the front part of the shell.
Drill a hole the size of the diameter of the shotgun shell primer. So that when the detonator assembly is placed in the shell, the lip around the cup end of the primer is still on the outside of the shell.

</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">code:</font><hr /><pre style="font-size:x-small; font-family: monospace;">
________________
\\_ __/ \
|-_|__ &lt;- Insert detonator assembly in here
// \________________/
^ ^
Fins CO2 Shell

</pre><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">Another point would be to add a fin design to the back of the shell for stability in flight to the target.

Sorry about the crappy pic. If I have time to illustrate the design further on a paint program I'll post it.

<small>[ November 13, 2002, 01:57 AM: Message edited by: 0EZ0 ]</small>

[Arkangel]

I may be being a dummy here, but I keep getting this message: "HTTP1.1 STATUS 403 Remote Access to this object forbidden This file cannot be directly accessed from a remote site, but must be linked through the Brinkster Member's site."

Anyway, I wouldn't be inclined to have anything too sensitive in this projectile. Personally I'd be inclined to have a fin assembly as suggested by OEZO, but have a delay fuse sticking out the back of the projectile. This will take fire from your propellant, and with appropriate testing you should be able to have it burst at a fairly predictable range. The sort of fuse I'm thinking of is like you would use in an aerial star shell.

I'm on the lookout for an old hydraulic ram to make something very similar :D

[Harry]

Instead of BP, have you considered compressed air?

Harry

[Anthony]

Drag the link to an empty IE window to view the picture <img border="0" title="" alt="[Wink]" src="wink.gif" />

I don't think you'll need that tree for support, the mass of the gun with that support frame, and it being on wheels, I reckon there's plenty of mass to abosrb the recoil from such a light round.

I'd be inclined to make a form of cartridge to load this thing. It's simply be a thin paper (or plastic, metal) tube, either with the CO2 cart in one end, or if the pipe isn't wide enough to allow that, the tube glued to a narrow point of the CO2 cart. It's hold your powder charge and an electrical ignitor along with, say 6" of doubled cored wire. These things would take a few minutes each to make up and to load you'd just have to remove the pipe cap, push the round into the breach, feed the wire end through a central hole in the pipe cap, screw the pipe cap on, twist the wires to your ignition source and away you go. For extra speed, you could put a plug on your ignition source and another on the rounds, then simply snap them together.

If you want something besides explosive rounds to try, cut the neck off of a CO2 cart and cast it full of lead. These things have great penetration when gotten up to speed :)

[NoltaiR]

reloading would be easy.. just a matter of

1,unscrewing the cap

2,cleaning the leads of any residue or build-up

3,placing new steel wool

4,adding another round

5,adding BP for the lifting charge

6,screwing back on

That should be simple enough. A new idea that I have had would be to use a good LE such as flash and the initiator would simply be a cap made for shotgun shells (you can buy the individual ones for shotgun shell reloaders).

The cap should fit tightly into the opening in the CO2 cartridge

[Arkangel]

I think the problem you're going to have with any such "fuse" is that unless it hits a hard surface dead on, you'll end up with a dud.

How are you going to ensure that this projectile doesn't tumble in flight?

[NoltaiR]

I think that the CO2 cartridges are heavy and aerodynamic enough to keep from shaking while in flight.

And if the shotgun shell primer cap is used for initiation, then rather than a nail being used, I believe a BB superglued to the center of the cap should be better.

[A43tg37]

Noltair, to make this artillery piece quicker to load, why not grind some of the threads of the cap and pipe off in an "interrupted screw" fashion (this could possibly be done easier if you were using a solid pipe plug instead of a cap), like is done on actual artillery pieces. This would create the problem of requiring obturation (blocking of the gases coming through the unthreaded areas), but I assume with your welder's skills you could make something that serves this purpose well (although, considering....a pipe cap like you're using now, rather than a plug, might actually provide obturation itself, as the threads, even though cut in interrupted screw fashion, are all inside it; however, it would be slower to screw and unscrew in an interrupted screw configuration than a plug would be). And finally, about keeping the shell from tumbling in flight: It seems that since the idea of using a rifled slug in a smoothbore barrel (shotgun barrel) instead of a rifled barrel and regular slug, works pretty well, someone would have came up with the same principle for a smoothbore cannon. Well, it turns out they did: check out <a href="http://www.civilwarartillery.com/projectiles/rifled/FAOIIIa64.htm" target="_blank">http://www.civilwarartillery.com/projectiles/rifled/FAOIIIa64.htm</a> . This shell uses vanes that are actually an integral part of the shell itself, to obtain accuracy and range that is almost as good as a shell fired from a rifled cannon (well, at least according to that site's webmaster, when I emailed him). While you probably don't want to go about casting one of these in metal, even with all the info available from Backyard Metal Casting, it shouldn't be too hard to make a hardened (with sodium silicate or something) paper-maiche nose adaptation with a "vaned" design similar to the Carkeet shell, for use on CO2 cartridges (of course, an adaptation like this could easily be put on blunter, less aerodynamic projectiles, thus allowng a greater range of projectiles to be fired from your artillery piece).

<small>[ November 13, 2002, 09:48 PM: Message edited by: A43tg37 ]</small>

[Arkangel]

GREAT post A43. I've never seen anything like the Carkeet shell before, but I reckon it could work quite well both for Noltair's projectiles AND with my spin stabilised rocket project (current thread in pyrotechnics). You make me veeerrryy happy!

I've been thinking of casting nozzles with plaster of paris, but this would suit itself perfectly to that. I just need to make a die, then a bunch of latex moulds and I can cast spin inducing Carkeet nosecones for my projectiles :D p of p might not be the best thing for Noltair, as the shock is going to be greater, and you don't want it breaking up as the projectile moves up the barrel <img border="0" title="" alt="[Eek!]" src="eek.gif" /> However, for me it should work fine.

I like your idea about removing sections of the thread, that should make reloading a lot quicker, especially if combined with some kind of cartridges......Noltair, what do you have against that idea? I know your system would work, but I like to be able to do some preparatory work (like cartridge building) sat listening to the radio over a beer <img border="0" title="" alt="[Wink]" src="wink.gif" />

Once again A43, great post :)

<small>[ November 13, 2002, 04:24 PM: Message edited by: Arkangel ]</small>

[0EZ0]

Ok finally got some time to show a rough diagram of a CO₂ shell design :p .

<a href="http://www.boomspeed.com/0ez0/CO2shelldesign.jpg" target="_blank">http://www.boomspeed.com/0ez0/CO2shelldesign.jpg</a>

From Arkangel
</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica"> Personally I'd be inclined to have a fin assembly as suggested by OEZO, but have a delay fuse sticking out the back of the projectile. This will take fire from your propellant, and with appropriate testing you should be able to have it burst at a fairly predictable range. The sort of fuse I'm thinking of is like you would use in an aerial star shell.
</font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">I was also thinking about having such a fuse added to the shell. I added it to the pic <img border="0" title="" alt="[Wink]" src="wink.gif" /> . Nothing is to scale, it is just a quick mock-up of a design. Comments? Suggestions?

[Arkangel]

Yep, I get the idea. It combines elements from both designs, and you should be assured of the shell exploding one way or another. It certainly seems feasible. I'm just curious what primary you'd use, something that can take a fair bit of shock :)

[NoltaiR]

Oh I have decided against the idea of having a homemade primary (well at least for now) in there because just the blast that would result from the cartridge leaving the barrel might be enough to initiate it. What I am doing is just filling the cartridge with my homemade BP (which over the years has come to be quite impressive) so that on impact the percussion cap will detonate spraying sparks on my BP which will set it off. Of coarse this will not be as effective as an HE but it is probably safer for the time being.

[Liam C.]

I like the picture OEZO... How would you suggest putting the fins on other than epoxy?

I myself have tried epoxy on experimental projectiles in the past and many of the rounds would lose one or two fins as soon as the rounds were launched (we'd find them up to a dozen feet from the launcher) causing them to keyhole our targets, which were made from 1/4" plywood, rather than strike head-on. After those tests, I kind of gave up on the idea of attaching fins to the little cartridges.

I believe that it's actually easier (at least for me anyway) to make a 'tail fin' assembly, and attach it to a CO2 cartridge that's had the bottle neck cut off from it. Somewhere in my garage is an empty round (a left-over from those tests I mentioned earlier). If you're interested, I'll make a serious search for it and take a couple pictures of it for you guys.

Anthony suggested making a form of cartridge for it for quicker reloading. That is an entirely 'doable' job there. What I was doing was intended for mechanical firing, but I suppose that it could be modified for electric firing as NoltaiR envisions. I was using emptied shotgun shells. Cut the crimp off the front, empty the shot (saving the wad), insert the new 'round' and reseal the edge of the shell with wax. For our long rounds (lengthy tail assy) we had to modify our shell casing a bit, but for the fins you guys are planning you shouldn't need to do anything to it. Rather simplistic, but they worked...

I suppose you could also try the cork trick as described in 'The Black Book Companion'. I've never done it but it looks interesting nonetheless.

[NoltaiR]

Well I had a go at making my first mini-cannon today (3/4" diameter barrel). The design was made completely out of wood except for the barrel itself because I wanted to do a quick but worthy job. Obviously this looks nothing like the first idea I had sketched out but I think it will work so long as my rounds don't get too heavy (I think casting them with lead would probably be a way to make them too heavy).

Anyways here are the pics of my gun (cut and paste).

side view:
<a href="http://www28.brinkster.com/emcatalouge/forum/side.jpg" target="_blank">http://www28.brinkster.com/emcatalouge/forum/side.jpg</a>

front view:
<a href="http://www28.brinkster.com/emcatalouge/forum/intimidation.jpg" target="_blank">http://www28.brinkster.com/emcatalouge/forum/intimidation.jpg</a>

pic of the end cap with holes drilled for electric leads:
<a href="http://www28.brinkster.com/emcatalouge/forum/cap.jpg" target="_blank">http://www28.brinkster.com/emcatalouge/forum/cap.jpg</a>

edit: and I know you guys are going to think that the pipe is just going to slip out when it fires off, but with the way I designed it, the wooden holes will actually tighten even more around the pipe when there is any kind of movement along with the fact that it took a sledge hammer just to drive the pipe through the holes (which I had made slightly smaller).

<small>[ November 14, 2002, 10:38 PM: Message edited by: NoltaiR ]</small>

[NoltaiR]

And I thought you guys might like to see the BP that I use for shots like this. Here is 400g of my homemade BP (made yesterday) made with 20% charcoal ranging from 200-400 mesh (having a range of mesh sizes seems to give it an extra kick of combustion when ignited in a confinement) 72% KNO3 and 8% sulfur. All three ingredients are poured in a low heat food processor and 91% isopryl alcohol is added so that it is damp (not soaked). They are blended for about a minute and then the BP is allowed to dry completely (for me this can take up to 24-30 hours because it is so humid where I live). The result is BP that looks like it has been run through a screen (in other words it is not powdered) and it is made up of charcoal of different sizes coated in sulfur and recrystallized KNO3. The finer ground charcoal will be burnt off immediately when ignited in the open (unconfined) and the larger grains of chargoal (approx 200 mesh) will be thrown off as sparks.

I burned 7g for this picture on a peice of paper (so I would have time to back away and I wouldn't have to waste a fuse).

<a href="http://www28.brinkster.com/emcatalouge/forum/bp1.jpg" target="_blank">http://www28.brinkster.com/emcatalouge/forum/bp1.jpg</a>

<a href="http://www28.brinkster.com/emcatalouge/forum/bp2.jpg" target="_blank">http://www28.brinkster.com/emcatalouge/forum/bp2.jpg</a>

<a href="http://www28.brinkster.com/emcatalouge/forum/bp3.jpg" target="_blank">http://www28.brinkster.com/emcatalouge/forum/bp3.jpg</a>

<a href="http://www28.brinkster.com/emcatalouge/forum/bp4.jpg" target="_blank">http://www28.brinkster.com/emcatalouge/forum/bp4.jpg</a>

[NoltaiR]

In about 3 hours I will be firing it off so check back.

[DarkAngel]

I had an idea of a design for faster reloading.
It's simply a capped barrel where a part is cut out with a bigger barrel shoved around it.
A metal rod is welded on the smaller barrel that acts as a handle.
Two small holes are drilled in the cap,in each one an electrical wire is inserted and on them there are two metal plates attached.They will conduct the current to the bridge wire in the cartridge.
The cartridge is made like Anthony described only with two small pins in them that will make contact with the plates on the cap.
There is a section cut out of the outer barrel like seen on the picture where the handle will move through in order to close the canon.

Load your cartridge inside the barrel and push it downwards,push/turn the handle and it's locked ready for firing.

<a href="http://entersection1.virtualave.net/Pictures/Load%20Mech1.JPG" target="_blank">http://entersection1.virtualave.net/Pictures/Load%20Mech1.JPG</a>
Here you see how the canon and the cartridge look from above in open view ready for loading and how it looks while closed.

<a href="http://entersection1.virtualave.net/Pictures/Load%20Mech2.JPG" target="_blank">http://entersection1.virtualave.net/Pictures/Load%20Mech2.JPG</a>
Shows the inner barrel from side view.

<a href="http://entersection1.virtualave.net/Pictures/Load%20Mech3.JPG" target="_blank">http://entersection1.virtualave.net/Pictures/Load%20Mech3.JPG</a>
Shows how the end cap could be made.

Don't attach to many importance to the picture of the cartridge it only describes the ignitor and the idea,i know that the seize of the Co2 cartridge isn't right but i already drew the barrel and didn't feel anything for it to do it again.

Some gasses could escape through the "lock part" this may be reduced by a little more propellant.

The Co2 cartridge may get stuck after it reaches the part that's cut away and where the not cutted part starts.
It could be prevented by using a projectile with a cone on top i think.

Improvements/suggestions are welcome.

<small>[ November 15, 2002, 02:13 PM: Message edited by: DarkAngel ]</small>

[Sgt.Starr]

Hey guys, I'm probally missing something, but why not use a 3 in shotgun shell minus the payload? Or, do you really want the electrical firing mechanism? You could modify the BP load to accomidate your barrel strenght, cartridge weight and range, with some practice. I'm assuming that CO2 cartridges are about the size of a shotgun shell, keep the plastic wading so that your fins wont be damaged(maybe shorten the wad) with your welding skills your should be able to concoct some firing mechanism. Hope this isnt repetitive or straying from your original idea, just thought that would be more efficient and faster for loading and firing. <img border="0" title="" alt="[Wink]" src="wink.gif" />