How to make homemade mortars

[kaylen]

Please tell me how to make homemade mortars or a sight that tells me how.
also try this fill a sprite can with any fast burning oxidizere black powder,flash powder nitro, hmtd ,acetone peroxide so on so fort put on a 1 ft visc fuse bury it leaving the fuse out and see wat happends (a miniture earth quake ) cool

[CragHack]

did you know that metals can react with HMTD and acetone peroxide to form heat, heat enough to cause the peroxides to explode? didn't think of that did you? get the fuck out of here. try and seach the net yourself asshole.

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"If you must, do it with intelligent people, at least they know how to talk to the cops."

[Pyro]

Honestly, with a post like that this topic should be immediately closed. You think you'd get helped for a mortar, go here www.wierdpier.com (http://www.wierdpier.com) and goto their forums, ask someone there, they'll tell you a procedure.-Pyro

[Cricket]

NBK2000's PDF. If you ask about where to get this, you don't need it.

[Bitter]

It's also in the wrong section, but that's another story. (Improvised Weapons, mister).

[Anthony]

I know HMTD is incompatible with nearly all metals, but I thought AP was ok with metals? Kitchen Improvised Blasting Caps agrees. Just wondering because I got some 10mm Al tube for caps thinking it'd be OK with AP.

[BoB-]

I dont know man, in a can theres a lot of room for the AP to "rattle", I dont understand the need for a high explosive, actually....I cant really understand your post as all.

[shady mutha]

The paladin press book 'professionals guide to pyrotechnics' has a firework mortar design made from strong cardboard.As for military grade the IRA used gas bottles filled with A.N based explosive for mortar rounds.They used blackpowder for the propellant.Delta press has a 'beer can mortar'book for $5.

[Anthony]

Home made mortar - length of steel pipe (preferably seamless) threaded at one end and an end cap. Simple.

[Foodos]

Kaylen: If you have the means to make AP, HMTD, and otherwise then you should have no problem finding plans, or improvising your own mortar.

Anthony: I was thinking along the same lines, especially since many people dream of using Brass empty shells with AP as small crackers, ive read a few posts on how people used aluminum shells as well.

[blackadder]

HMTD is corrosive to metals, because of its extreme excess of oxygen. Why isn't AP corrosive to metals? They are both triperoxides, and both have the same amount of oxygen atoms according to "Improvised primary explosives".

AP formula:

C₉H₁₈O₆

HMTD formula:

C₆H₁₂N₂O<SUB>6</SUB>

Now that has to be some faulty information, hasn't it! I think the AP formula is wrong, because in another pdf I read that AP has a formula of:

C₆H₁₂O₄.

I believe that the latter formula for AP is correct. Can anyone fill me in on this? What is the correct formula of AP and WHY doesn't it corrode metals as well as HMTD, if it has the same number of oxygen atoms than HMTD does.


[This message has been edited by blackadder (edited April 13, 2001).]

[blackadder]

OoTSCoO, you are still given respect for having the right attitude towards the forum (which you have demonstrated in your previous post), but please improve your spelling, there is a spellchecker to help you as well.

[CodeMason]

blackadder: Both those AP formulas are right, it's just that the former is the trimer, and the latter is the dimer.

[Gollum]

The problem with mortars like that is that they generally offer very poor accuracy. If you know how to build proper mortar rounds, and are knowledgable in meteorology then you can get pretty accurate.

[CragHack]

meteorology...? what are we trying to predict the fucking weather? (::licks finger, sticks it up in the air:: "hmm, might rain")

also after rereading the posts no one has mentioned how unstable AP and HMTD are when considering shock. you try and launch a can, with AP or hmtd in it, with a mortar and you will be picking the tube of the mortar out of your skull for weeks to come.

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"If you must, do it with intelligent people, at least they know how to talk to the cops."

[This message has been edited by CragHack (edited May 17, 2001).]

[Gollum]

Meteorology is important because the rounds will have different courses depending on the air pressure, ambient moisture, altitude of the round, and so on. This is why meteorologists can always be found travelling with artillery. Big guns with big shells need big knowledge. Just firing at random angles could end up in you or one of your comrades being hit by shrapnel from the round (Provided you're using a proper round).

[PYRO500]

uh... humidity? I dont think that will matter seing our cannons are improvised, in fact the only major deciding factor that matters here is the wind, and it dosent take a meteroligist to figure how that will effect your morter

[BaDSeeD]

LOL

Ohh my god.

I can't believe how technical everyone is getting here. How fucking accurate do you think a mortar is going to be when you use a "beer can" for a projectile, or a piece of gas line or sewer pipe for a launcher. Get real people. Does anyone here have any practical use for a mortar anyhow? What ya gonna do.... go hunting? The only practical use someone here might have for a mortar... is as a terror weapon. Any kills from it would only be a bonus.... how accurate does it have to be then?



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BaDSeeD
Knowledge is the true power, ignorance will bring your demise.

[Gollum]

Well if you really are using it as a terror weapon, you should make the beer cans special. Make them explode on impact with the ground and send Willie Pete flying everywhere (White Phosphorus, see NBK's post). Or if you have electronics skill make it explode 50 feet above ground to kill and maim everyone within a few hundred feet. All you need to do is have consistant weight and shape for your mortar round, and a consistant ammount of quality propellant launching it. With geometry and proper weather knowledge you can get it to be quite exact.
PYRO500: Moisture in the air is important because it adds resistance to the movement of your round. On a foggy and windy day it can mean the difference between the round flying 500 feet or landing right at your feet.

Here's a good read for anyone who likes this kind of stuff: http://www.adtdl.army.mil/cgi-bin/atdl.dll/fm/23-90/toc.htm

And remember, if you're going to do it, do it well!

[PYRO500]

ok, humidity is never gonna make that big a diffrence, your beer can is likely to tumble in flight witch will eliminate the need for accurate calculations, granted geometry is useful here, the only factor that will effect the tdj. of your cannon is wind.

[madman]

A variety of grenade launchers can be fabricated from metal pipes and fittings.Ranges up to 600 meters can be obtained depending on length of tube,charge,number of grenades,and angle of firing.
Material required.
Metal pipe,threaded on one end approx 2-1/2 in. in diameter and 14 in.to 4 ft long depending on range desired and number of grenades.
End cap to fit pipe.
Black powder,15 to 50 gm
Fuse(any)or Electric initiator
grenade(homemade)
rags about 30 in.x30 in.
drill
string
Method.
1.drill small hole through center of end cap
2.place blackbodies and fuse in paper bag and tie with string.
3.thread fuse through hole in end cap and place package(blackpowder)in end cap.screw end cap into pipe,being careful that the package in not caught between the threads.
roll rag wad so that it is about 6on. long and has approximately the same diameter as pipe.push rag into open end of pipe untill it rests against package
5 pop in the grenade.
On another note I saw the Australian army mortars,they can fire almost 5 km,the fire controller has a hand held computer that works everything out.

[Demolition]

Madman,how do you manufacture your grenades?
Demolition

[madman]

Demolition I have never used that devise and have never produced a grenade.The information I have is.
Material required.
Iron pipe,threaded ends 1 1/2 to 3" diam,3" to 8"long.
Explosive or propellant
nonelectric blasting cap.
fuse.
drill.
Just screw the cap on one end ,make sure the blasting cap is in the middle,fill her up cap it.
An improvised method of launching a standard grenade 150 yds or an improvised grenade 90 yds using a discarded ammunition container.
Material required
Heavy cardboard container with inside diameter of 2 1/2 to 3" and at least 12 in.
Black powder-8 grams.
fuse
grenade
Rag,approximately 30 in x 24 in
paper.
1.Discard top of container.Make small hole in bottom.
2.measure off a piece of fuse at least as long as the cardboard container.Tape one end of this to the fuse from the blasting cap in the improvised grenade.Be sure ends of fuse are in contact with EACH other.
3. place free end of fuse and blackpowder on piece of paper.Tie ens with string so contents will not fall out.
4place packasge in tube.Insert rag wadding.Pack so it fits snugly.Place pipe grenade into tube.Be sure it fits snugly.
5.Insert fuse through hole on bottom of launcher.Make sure it goes INTO blackpowder package.
6.bury container about 6" into ground at 30*degree angle.
7.fire on enemy.

[mark]

Weapons of error? killing and maiming? Who are you fighting? Keep the hell out of the east bay, if you dont mind.

A thick cardboard tube with a 3/4 inch diameter inside can be used to launch cratermakers so they go off in the air. This isnt a "weapon o terror", just something cool to aim over the ocean at the beach.

Also, birdbombs are quite cool. Theyre flying m80s that go for 100 feet. You shoot them from guns.

[ST]

<img src="http://server3004.freeyellow.com/stx/mortar.jpg" align="left">

The mortar is just a pipe sealed at one end, the ammunition is the hard part,what described above are simply cannons.
Mortars are effective because they are capable of putting a lot of explosive in the air in a short time, therefore the round must not leave anything within the tube once fired, this allows the ammunition to be continually fed into it.
The picture shows a round that leave nothing behind and is fired out of a simple steel tube.
As the round hits the end of the tube, the shotshell full of powder is forced beack onto a firing pin igniting the powder charge and firing the round.

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ST
posted pictures (http://server3004.freeyellow.com/stx/forumpics.html)

[PYRO500]

I would have a thin piece of metal holding the main impact hamer to strike the primer, so that when it smacks the ground it will crumple and not slide back and strike the primer prematurely

[Mr Cool]

Blackadder: how can you have the formula for HMTD in front of you and claim that it has an ecxess of oxygen?!?!!?!?!?!??! It needs 12 more oxygen atoms to even have a neutral oxygen balance!
(sorry, I don't know anything about home-made mortars, or why you'd want one)

[Agent Blak]

ST,

Is this just an Idea or has it been proto-typed and tested?
Also you could try a fused system; this would be great for employing an Arson or shrapnel.

------------------
A wise man once said:
"...There Will Be No
Stand Off At High Noon
... Shoot'em In The Back
And, Shoot'em In The Dark"

Agent Blak-------OUT!!

[10fingers]

When the relatives are over there are a lot of beer cans flying through the air and I can say with certainty that they are not very aerodynamic or accurate.

[ST]

Agent Blak,

No, its just an idea, i for one would never push something like that down a tube next to me .. I dont know what casing/propellant combinations would work, it just seems like a feasable idea that can be worked on.



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ST
posted pictures (http://server3004.freeyellow.com/stx/forumpics.html)

[SawedOff8gaugeman]

<font face="Verdana, Arial" size="2">Originally posted by Agent Blak:
ST,

Is this just an Idea or has it been proto-typed and tested?</font>

It's not his idea. Can be found(with more detailed istructions and no idiotical bugs, fused version) in "Ragner's book of homemade weapons" as well as in NBK2000 pdf.

There's not any bleed holes in the picture around the upper portion of the shotshell chamber. BIG MISTAKE!!! I bet if it would work, at least it could leave the empty shell behind in the tube =(

[ST]

I thought i had thought it up.... but id never claim it as everything this simple would have been done before.

Tell me what these "bleed holes" are for? i can see any need but you seem assured with yourself that its necessary.

And what the fuck do you want the shotshell left in the tube for, the whole point is for it to not be there.

What do you want a fused shell for? hits the ground and waits a bit before exploding? explodes in air? surely its best to go off as soon as it hits.

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ST
posted pictures (http://server3004.freeyellow.com/stx/forumpics.html)

[This message has been edited by ST (edited June 26, 2001).]

[Mexican Pizza]

ST, SawedOff8gaugeman was refering to how your design would leave the shor shell in the tube, I think. Bleed holes are nessary for the gasses from the burnt powder within the shot shell to escape the confinement of the tube.

[ST]

no more comments from me until someone actually looks at the picture.

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ST
posted pictures (http://server3004.freeyellow.com/stx/forumpics.html)

[PYRO500]

Why would you want bleed holes? they would make the morter loose power! you waant as much gasses as possible behind the morter to launch it.

[nbk2000]

This is a picture of a stokes mortar bomb showing the bleed holes. It too used 12 guage shells of propellant.

http://oldguns.net/5189.jpg

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"The knowledge that they fear is a weapon to be used against them"

Go here (http://members.nbci.com/angelo_444/dload.html) to download the NBK2000 website PDF.

Go here (http://briefcase.yahoo.com/nbk2k) to download the NBK2000 videos.

[Anthony]

But if I'm looking at that picture right, the 12ga cartridge is base down unlike ST's pic. So the only way out is through the bleed holes, whereas in ST's the cartridge is base up so the open end points straight down into the mortar, so I'd think no bleed holes needed.

Simplier design cartridge down though as the firing pin in the mortar acts directly on the primer of the cartridge.

I'm guessing that wide ring keeps the cartridge from being ejected on ignition and leaving the empty cartridge in the mortar.

I wouldn't have thought a standard 12ga propellant load would have enough umph to fire something that big and heavy a long distance - you learn soemthing new everydayhttp://theforum.virtualave.net/ubb/smilies/smile.gif

[ST]

OK, thanks Anthony for noticing.

I just downloaded the NBK pdf and see what you lot are talking about, and where the confusion was, bensons design looks much the same as the picture NBK has posted.

Problems i see from an improvised viewpoint, the shell must be made perfectly to have any hope of working if the firing pin is at the bottom of the tube.

The body must be a perfect fit for the tube, "nipple" welded perfectly centered and firing pin in centre of end cap to have any hope of working. Ragnar also doesnt mention if the shotshell stays in the tube or not.

Ragnar mentions how the endcaps constantly need replacing, Using a design that doesnt use a firing pin in the mortar itself would let you build up the base with welded plate steel, taking away the need to replace it.



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ST
posted pictures (http://server3004.freeyellow.com/stx/forumpics.html)

[SawedOff8gaugeman]

Now I "actually looked at the picture" and noticed it's a good construction!! I couldn't see the cartridge was downwards at first.

I think the cartridge would be ejected more surely on this model and again, Ragner's construction actually sucked http://theforum.virtualave.net/ubb/smilies/tongue.gif

[kingspaz]

has anybody thought of re-activating deactivated mortars? it could be a better option as the tube would be designed for the purpose and able to easily take the pressure.

[Ragnar]

As far as sighting is concerned, a good rout to go would be that similar to the swiss 60mm Commando(?) mortar which uses a sling with ranging incriments printed on it.
To adjust range the firer simply places his foot inside the sling on the appropriate range mark and pulls firmly up on the tube.
Good Idea for on-the-go firing.

Of course.....a lot of experimenting for consistency with semi-prescision rounds would be required.

[SMAG 12B/E5]

I don't mean to offend anyone on this post, however the material presented appears to indicate little experience in actual mortar construction. My dreams indicate that an improvised mortar of two inch bore launching a round fabricated from 1 1/4 pipe nipple, cap and bell reducer with 3/8 inch tail piece containing a shortened 45 long colt cartridge containing 1/2 tsp FFG BP and the powder from one 30/06 cartridge (in tissue paper) wrapped around the vent holes in tail piece will travel approximately 250 m.
AP is unsafe to use in rounds, ignition cartridge must be retained in stabilizer tube, stabilizer tube (base tube) must be vented, main propellent can be attached to exterior of tail, fuse must be sealed from propellent gases and should be bore-safe, if point detonated, round must be flight stabilized
The 60 mm mortar used in WWII by allied forces is an excellent device to dream about. It is simple, easily manufactured, practice rounds and unloaded rounds are available, the bipods and sights are still available at a reasonable cost, blueprints of the M52 (???) fuse are available...
Dream safely...

[SATANIC]

In regards to the commando mortars, they are not very accurate (even less accurate than most) and even if you do get a good shot in, there is no guaruntee it will happen again. the mortar is thrown off every shot, as it is not 'bedded in' properly. Also, the commando mortars have the tendancy to break legs, as the shock of the propelant blast is enough to break legs, when on soft ground or sand etc.

[Hex]

I wouldn't try that mortar round design of ST's if i were you, kids. A firing pin set in the front of a round like that would be very likely to "set back" on firing - and set the round off inside the mortar tube. Think how you get pressed back in the seat when someone floors a car from a standing start, and then consider how much faster a mortar round will be accelerating up the barrel. Even with a spring or a shear wire holding it in place I wouldn't go anywhere near that sort of design. The British Army tested a simple rifle grenade design in WW1 with a front mounted firing pin - and abandoned it immediately as it kept killing the firer. I'm afraid you're going to have to use an inertia pellet/creep spring arrangement if you want detonate on impact rounds.

[Brushburner]

Does anyone think this sounds feasible? you can make a impact-detonator by having it so a nail, that is in the front of the mortar round hit a fixed cap (forget what you call them, not into guns a lot) that would ignite whatever explosive that is in the round, I would suggest something as weak as pyrodex in this case, as it is not very shock sensitive (someone reply how to post a pic in a message and i do that, im not good at putting ideas into words http://theforum.virtualave.net/ubb/smilies/smile.gif)

P.S. Hex, i would'nt have this so it was loose,possibly put it in something tight-fitting, like a rubber stopper. Then it would need to hit something, and just being fired wouldnt set it off (please correct me if im wrong but dont bash me lol)

[This message has been edited by Brushburner (edited August 01, 2001).]

[Anthony]

A person is considerably more massive than a firing pin and primers need quite a lot of force to set them off.

Was the rifle grenade in question one which catches a bullet? If so then the propulsion of the grenade is a different kettle of fish to a mortar.

[Demolition]

Instead of having such a sensitive primary like AP what about having a tube with a secondary explosive,eg,RDX,PETN,Picric acid in the bottom.Half way up use a weak glue to hold a solid metal pipe (which slides up and down the larger tube easily).This would then of course be poking out the front of the mortar shell so when it hits the ground it would break free from the hold of the glue and slide down onto the secondary explosive setting it off (like hitting it with a hammer),this then would set off the main charge,something like ANNM/Al could be used for this.
Could look something like this,

###_____
####II
####II
-###|II|
|----|II|----|
|***|II|***|
|***|II|***|
|***|@|***|
|***|@|***|
|***|@|***|
|***===***|
|*********|
--------------

# = ignore these
| = walls of mortar shell
- = base of shell
@ = PETN,RDX,Picric Acid
* = ANNM/Al explosive
= = Metal plate at base of pipe
I = Solid metal pipe
_ = Plate at top of Mortar round

(damn picture,I'm sure someone would be able to dram up something similar in paint)
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To be untouchable one must first surround himself with the strong.
Demolition

[This message has been edited by Demolition (edited August 04, 2001).]

[Hex]

That rifle grenade I was talking about was fired by a blank cartridge rather than a bullet pass/trap mech.
If you look through textbooks, you will hardly ever come across devices with front-mounted direct impact fuzes in anything except (hand launched) grenades. Don't underestimate inertial effects - shells containing cast TNT have been known to detonate in the bore because of tiny air pockets undergoing adiabatic heating due to acceleration. This is obviously unlikely to happen in a much lower velocity situation like a mortar, but I'll say it again - there's no way I would stand next to a home made mortar which was about to fire with a direct impact firing pin in the nose, no matter how stiffly it was held in place.
Armies like simple weapons - but none of them have ever wanted to use fuzes like this in a similar weapon. Why???

[Lagen]

I agree with Hex on the inertia effects - the pressure generated is mainly a function of acceleration and density/shape of the object being accelerated. Thus a small metal object could well generate more pressure (over a smaller area) than a large human body.

[simply RED]

What is the construction of the military mortar rounds? What primer do they use in the detonator? What is the construction of the detonator? I think a home made mortar is something super dangerous, it could be improvised but the construction must be copied from a real military one. The main explosive must be something insensitive like RDX/PETN plastic, urea nitrate, ANNM, TNT. Never peroxide or nitroglycerine must be used... I also would feel a real FEAR standing to firing home made mortat...

[zaibatsu]

PETN is still pretty sensitive, you can detonate it with 1mg of lead azide.

[Anthony]

Fair enough, can you suggest a more suitable method?

[Hex]

The simplest military impact fuses generally consist of a striker mounted on a heavy pellet, which moves in a tube. The detonator assembly is at the forward end of the tube. On launch, the pellet is held back by acceleration at the rear of the tube. On impact, the shell stops suddenly, but the pellet doesn't. It travels up the tube, overcoming the resistance of a creep spring between it and the detonator and the striker impacts on the firing assembly.
There will always be a safety device which locks the striker pellet in place until it leaves the barrel. In mortars, this is often a bore riding pin which is spring loaded and is ejected to release the striker.

[Tony Montana]

If your serious about weapon systems check this out, it takes fucking ages to load but is worth it:
http://www.isr.ist.utl.pt/library/incoming/math/www.pdox.net/%257Ededekind/books/Physics/Principles%20of%20Naval%20Weapons%20Systems.pdf

[Anthony]

Sounds like a good system Hex, it'd be difficult to fit into small devices but for mortars it would be good.

[irish]

Silverleaf, you have got to be a fucking idiot is you think nitrogen triiodide is a good thing to use as a primary in anything let alone a mortar shell :mad: . Edit= just ignore the above it seems the post I was referring to is gone :confused: .

To add to Hex's post, I know someone who did a limited amount of experimentation with 10 Cm long Copper tubes with a precussion cap (from gunshop) in one end on an Iron anvil (made to fit the tube, with a hole drilled through it and a nipple for the cap), and a steel striker that would slide up the tube in the other end. These where attached to an arrow and "fired" into the air to test with good results ie they fired the cap most times on contact with firm ground.
No safety was tested nor was a detonater attached to the cap but this is on the long list of things to do (oneday :rolleyes: ).

[majik]

Hi there all. I have a tried and tested method for constructing a (fairly accurate) mortar.

I used to steal co2 canisters from fire extinguishers at school; the kind that have a separate co2 canister screwed on. This canister is in the shape of a bullet already so that's a bonus for aerodynamics.

On 1 end of the canister is a hole with an aluminium cap that needs to be pierced (by a nail for example) to let the co2 out. around this is a screw thread which was originally used to attach canister to extinguisher. you use this to screw on a short length of tube to which you weld 4 fins that do not exceed the diameter of the canister itself. This way you can stick the shell in a launch tube.

I was lucky to find a tube of the same diameter (roughly) as the canister. You fit the launch tube with an end cap, to which a steel nail is welded exactly in the center on the inside, long enough to reach the aluminium seal through the screwed-on pipe.

The launch tube is welded to a sliding hinge(made with a curtain rail system) which in turn is attached to a wheel jack (or whatever you call the thing you use to lift a car up when changing the wheel) which you use to adjust elevation.

The whole assembly is mounted on a studded heavy steel plate (studs on underside for grip) Recoil is considerable but nothing compared to an expl. charge as a large part of the propellant is expended in flight and not all inside the tube. Drop the projectile in and it comes whooshing back out with a billowing cloud of gas in it's wake!

1 problem i encountered was that sometimes the seal didn't break and i had to wait around for ages to get the projectile back out again (carefully) for fear of the thing going off! I suppose a longer tube would have given it that necessary extra bit of momentum needed to ensure seal breakage.

I never attached an explosive of any kind to the projectile but i'm sure there are enough effective methods to do so relatively easily. I was thinking of using a bulletprimer, nail and spring system for impact detonation, the spring being of the necessary strength to prevent the nail from hitting the primer at launch.

The furthest i ever shot this thing was +/- 100 meters which is surprising as the co2 canister itself weighs quite a lot. Guess there's something to be said for compressed air eh? I reckon if someone who knows what they're doing with acces to a machine shop put their mind to this, they would get the thing to fly a lot further. I am but an amateur i'm afraid.

When i fired 3 consecutive rounds, they all landed within a square of 10x10 meters +/- 100 meters away. The IRA employed a similar device in a mortar attack on 10 downing street. They didn't count on bomb-proof curtains though. If anyone is interested i can put up a rough sketch of the design.

++++++++++++++++

How about you edit this post yourself so it's not a 26 sentence monoparagraph?

You know, those little spaces between groups of sentences that allow a person to seperate a though group from another, but different, thought group?

You may wish to do this quickly, before I next visit this thread, or I'll do it myself and remove you while I'm wasting my time correcting your crappy grammer for you.

NBK

++++++++++++++++
[No need to create a separate post for the following.
Rhadon]

Sorry about the grammar, got a little overenthusiastic whilst typing :o

Hope the edit has made it easier to read.

[tasm]

I am new here and trying to avoid HED, but I felt this thread left a few things unanswered.
Terms: cant - the deviation from level of an object
mil - unit of measurement used in mortars. 1 degree = 17.777 mils
Aiming:
First, to have a semi accurate mortar you need to be able to have a definite way to measure the cant of the tube. Probably the easiest way to this is with a surplus M2 Compass (has a level bubble with mil increments). The compass is simply laid sideways against the tube and the cant can be read in mils. This information with a consistent charge can be used to create a charge book for different ranges.
Second, to aim the mortar in a "direct lay" type scenario, aim the tube at your proposed target and fire. Observe where the round lands and move your tube the in the direction of the target (and past the target) so you are now aiming approximately the distance between the target and the miss further than the actual target.
Creation:
I would highly recommend using scrap oil field drill pipe with a threaded end cap. Plumbers galvanized pipe just reminds me of a big pipe bomb.
Ammunition:
Rounds should be created in such a manner as to have a lip at least 1/8 of and inch around the primer if possible. This will prevent rounds from going off if dropped. The vent holes in the shaft are necessary to insure that the charge will stay in the round and not be spent in the tube. Also, the vent holes are used to ignite secondary "bag" charges you may choose to attach for longer ranges.
Safety:
Upon a hung or dud round slowly lower the tube to level with the ground, remove the end cap or retract the firing pin if applicable. Lean the tube forward gently shaking to dislodge the round having someone to catch the dud. Never attempt to remove a round with your hand or with a ramrod.
Finally:
I am no expert on mortars, but I do have extensive experience on the 60mm, 81mm, 4.2 inch, and the 120mm gun systems. If you have any questions I would be more than happy to answer them to the best of my ability.

[MMIV]

u could have look at WRM(white resistance manual) on improvised mortars it found usually on the net or p2p networks such Overnet, Edonkey2000 or Imesh. the mortar look like a mean bit gear and they the approx range is about 700 yards. :)

[nbk2000]

You can buy surplus mortar tubes and rounds.

The tubes have a hole punched in them, and the rounds are drilled, but you can cut the tube short above the hole and fix that, as you're not trying to get 6KM range out of it, as 1KM would be more than adequate for urban warfare, and the rounds can be repaired to be functional with an improvised fuze.

[Lawrence]

Just a thought on impact detonation devices, on some old film of bombs being dropped from airplanes I have noticed that there is a small propeller on the nose of the bomb,I have always assumed that this is a safety device that would screw the fuse, or some activating part of it into alignment,thereby rendering the bomb "safe" untill it is actually dropped.
It would not be hard to construct such a system for a mortar round,the prop would be driven by the airflow and would be attached to a screw thread inside the body of the round,this would then render the round live several seconds after launch by completing an electrical circuit for example,is this a viable idea?

[Bugger]

If your serious about weapon systems check this out, it takes fucking ages to load but is worth it:
http://www.isr.ist.utl.pt/library/incoming/math/www.pdox.net/%257Ededekind/books/Physics/Principles%20of%20Naval%20Weapons%20Systems.pdf
I only get "403 forbidden". What log-in name and password did you use on that site in Portugal (Technological University of Lisbon, I think)? Did you use a proxy server? Or, do you think you could e-mail it to me at swell002@yahoo.com ? Thanks.

Bugger.

[festergrump]

Lawrence,

I suppose that's a pretty viable idea. I'm wondering if the added drag would send the projectile off course, though. In the example of bombs being dropped from aircraft this wouldn't pose a problem at all because they're guided by gravity and not really intended to require a direct hit due to the massive charge of HE or incendiary. If the prop was in the rear of the projectile this would perhaps stabilize it some, but make the projectile much more complicated to manufacture. (problems with prop and propellant charge).

Another manner in which fans or props can be used (PMJB Vol 1, I think) is in the ignition of the propellant charge. This would be for anti-helicopter mortars. The idea is to have a fan facing upwards in the bottom of a tube (to avoid wind turning the fan) which would turn a generator or alternator in the event of a helicopters "wash" being too nearby. the alternator would generate enough electricity to ingnite the propellant charge and launch the projectile towards the heli.

I happen to like NBK's idea from his PDF to have a beer or soda can filled with cement as the mortar's projectile and attached to a steel cable to entangle the heli's props rather than trying to get a HE charge to take it out of commission. Read both PMJB and NBK's PDF...Great reading and both on the FTP. (NBK's is following every one of his posts, also).

[Bugger]

"Principles of Naval Weapons Systems.pdf" can be downloaded from:

http://books.pdox.net/Physics/Principles%20of%20Naval%20Weapons%20Systems.pdf

It is one of many PDF ebook files in the Dedekind physics and mathematics archives, on this site, the root directory of which is http://books.pdox.net/ .

Bugger.

[Tinton]

ST got it.
Tube
Nail on endcap of tube
Nail strikes primer, primer initiates, launches out, lands, detonates.

I would probably make the projectile out of something able to withstand the forces of the propellant. Just so you don't actually hurt anyone.(yourself!)

[GNAB]

http://www.militaryphotos.net/forums/showthread.php?t=78351

215.9mm Black powder mortar. Launches 16# bowling balls to 200 meters. Built from an oxygen cylinder. Check out the photos, especially the gallon ziplocs full of gasoline!!! This would be great for hunting rednecks in trailer houses.
Ya'll com'on down to Oklahoma and we'll punch some holes in Bubba's doublewide.
Now who wants to bore out a bowling ball and discuss what kind and how much explosive would be appropriate for entertainment value.

[eelfland]

When I was a kid a made a good many pipe-bomb grenades that were actuated by a roofing nail taped in position on the leading end, with the pointed end of the nail resting on the primer of a 12-gauge shotgun shell held inside the 3/4" pipe by a cap with a hole drilled through the center to hold my firing pin. A long rag tied to the other end of the grenade served both as a launching device and a flight stabilizer, making sure that the round landed on its firing pin. They worked great, as long as the grenade landed on a hard surface. The road in front of my house was pockmarked. I used six-inch nipples, mostly, with various charges, usually shotgun shell propellant, and not a lot of that.

A mortar to launch such a grenade could use a shotgun shell blank as its charge. I would highly doubt that the acceleration imparted by the charge would be sufficient to detonate the primer in the nose of the grenade, especially with the rag wadding to pad the shock, but I'd want to fire a good many empty pipe grenades, or ones loaded with just a primer and a simulated charge, before trusting a fully charged one not to detonate in the barrel of the mortar. It might be safer to glue the firing pin in place, but not so firmly that the shell's impact wouldn't dislodge it. Some experimentation would be in order.

The beauty of a mortar is that it is able to lob a shell over fortifications, rather than just busting through them. With the long rag streaming out behind these shells, it would be fun to practice firing dummy shells to gain accuracy before firing live ones, and it would be very cheap, too, since the dummy shells could be reused, and the propellant for the mortar could be just cheap black powder or Pyrodex. In the right hands, such a weapon could be a good way to keep the riff-raff out, too.

Sounds like fun to me. Takes me back 45 years to when I first started playing with fire.

[corz29]

I use the M5 homemade military propellant it is the formula:

-nitocellulose 81.95%
-nitroglycerine 15.00%
-barium nitrate 1.40%
-potasium nitrate 0.75%
-ethyl centarlite 0.60%
-graphite 0.30%

(the % are by weight)

[Bacon46]

Now who wants to bore out a bowling ball and discuss what kind and how much explosive would be appropriate for entertainment value

The links are to video and images of a 15lb bowling ball frag that I made a couple months ago. I used 2oz (56.5g) of KnO3/Al flash and an electric match for ignition. It would be easy enough to replace the electric match with a timed fuse and fire it out of a mortar.

The chunks of rubber/plastic on the scale are all I was able to recover of the ball. The largest piece weighed 6.8oz (192.77g) and was thrown over 50 yards (45.72 meters).

http://img531.imageshack.us/my.php?image=bowlingballfragcutuq3.flv

http://img234.imageshack.us/img234/2892/15lbimprovisedfragow8.th.jpg (http://img234.imageshack.us/my.php?image=15lbimprovisedfragow8.jpg)

http://img98.imageshack.us/img98/7876/15lbfrag005sr1.th.jpg (http://img98.imageshack.us/my.php?image=15lbfrag005sr1.jpg)

http://img452.imageshack.us/img452/9034/15lbfrag002sa6.th.jpg (http://img452.imageshack.us/my.php?image=15lbfrag002sa6.jpg)

[wetpowder]

ST got it.
Tube
Nail on endcap of tube
Nail strikes primer, primer initiates, launches out, lands, detonates.

I would probably make the projectile out of something able to withstand the forces of the propellant. Just so you don't actually hurt anyone.(yourself!)
You are answering a post that is 6 years old.:rolleyes:

[209]

Yeah, I went and looked at the date when I saw that Craghack posted a reply, I haven't seen him for a while.......

[megalomania]

The contribution of knowledge will always be appreciated by the future generations who have yet to discover this thread. Adding new info to an old thread is far better than asking a question out of the blue of someone who has not been around for half a decade (the Forum crime of necromancy, punishable by HED).

[Zer4tul]

ST got it.
Tube
Nail on endcap of tube
Nail strikes primer, primer initiates, launches out, lands, detonates.

I would probably make the projectile out of something able to withstand the forces of the propellant. Just so you don't actually hurt anyone.(yourself!)

As it is almost forth of July, and loud noises are not unusual, I have started experimenting with several mortar ideas. An idea i tried that builds on the one above was simply cutting a 1-2" slot in both sides at about 6" from the top of the mortar pipe, inserting a piece of lexan that matches the slot, and attaching a string/cord to the lexan piece. As with above, a nail or so is attached to the endcap.

The round consists of a shotgun shell that has been emptied, filled with propellant, and sealed. The shotty shell is then attatched firmly to the projectile that is about to be launched. (which in my case was simply a golf ball in a playdoh canister) The round sits on top of the removable piece of lexan, and when the string is pulled, the piece pulls out, and the round falls on nail. All at a nice safe distance. :)

[SuperScience]

This zip file contains two documents; one includes detailed plans for homemade mortars:
http://rapidshare.com/files/40548618/requested_files.zip.html
Hope this helps!