Recoilless Weapon

[Spotter]

I build a recoilless weapon like in the Book "Improvised Home-Build Recoilless Launchers", but without Cookies as Counterwight.
Has anyone build a thing like this? Any good Ideas for this "Baby"
When it is ready i send some Pictures. (3-4 Weeks)

MFG Spotter

[Ropik]

I made a panzerfaust as described in "Poor man's RPG". Effective and impressive, cheap too.

[nbk2000]

Picture proof or death as posers!

[Ropik]

I will try to take a picture of my panzer... If I can borrow a digital camera somewhere. But hopefully yes.

EDIT: Sloppy sloppy... I forgot that I have one picture already done
:rolleyes: .
Coming soon.

EDIT No.2: Here it is! My reenactment panzerfaust. Enjoy this picture, I will delete it later.

[streety]

Nice socks! :D

What are the fins made of? I assume they roll or fold up so it fits in the barrel?

[Ropik]

Yes, my best socks!
Fins are from plastic cover for papers, I just bought it in stationery. Strong enough, but the tape on the fins is because the edges likes tearing when they leave the tube.
Yes, they roll to fit the launching tube.

[Flake2m]

Looks very impressive Ropik.
I haven't read "Poor Mans RPG" but can you give some technical specs on your device?
I'd like to know the propellant use, range it has and how heavy the whole thing is to carry?

[Ropik]

Seamless tube, 32 mm ID, extra thickwalled for safety. In the centre 15 gms of black powder(if you can use commercial BP, it would take less), which shot projectile on one side and equivalent weight of sand on another. Recoilless, for 600 gms warhead range is about 30 meters, accuraccy is fairly good, I can hit a 55 gallon drum most of time from 20 meters.
Oh yes, and electric bulb ignitor is used to ignite the BP. Leads are pulled from rear of the launcher.
It is not very heavy, maybe 2,5 kg tube + 600 gms warhead + 600 gms sand. From this reason I resigned to "Improvised Home-Build Recoilless Launchers", this launcher is too heavy or too flimsy. No way.

[ossassin]

Is it strictly for reenactment purposes, or were you planning on using a HEAT warhead?

EDIT------------------------------------------------------------
Osassin was actually meaning, of course this was designed for legal use, but could you imagine that somewhere with no laws prohibiting this that someone could use a similar design with a HEAT warhead.

Zaibatsu

[Ropik]

Nice edit, Zaibatsu, because I am strictly legallish and even thinking about functional warhead makes me puke...
But if HEAT(or any else) warhead will fit into 600 gms of present warhead(you could use heavier warhead and heavier counterweight, but anyway range will decrease), I don't see any problem with substituting the sand-filled tin can with shaped charge:).

[nbk2000]

A one pound warhead, going 20-30 yards, is not much of a weapon, considering how you can throw that much weight that same distance, without the extra weight or drama of a "launcher".

Now, get it to 100+ yards, and you've got something going. ;)

[Barcy]

Looks interesting, so if one was to reduce the size of the load to say 200gr and slightly amp up the propellant the 100 yard range might be a possiblity. I like the launching tube set up.

I am curious about a few things.
What you house your charge in (the tubing on the rocket)?
Have you somehow managed to have an electrical contact for the load or do you have to still attach wires as a seperate loading stage (did not see any wires)?
Have you looked at any sighting devices?

[tiac03]

The new tube had a diameter of 4.4cm (1.73 in.), the propellant now weighed 95g (3.35 oz.); the projectile now measured 49.5cm (19.49 in.) and weighed 2.9kg (6.39 lb). The resulting projectile velocity was 30m/s (100 fps) which again made for a range of roughly 30m (100 ft.). The complete weapon now weighed 5,1 kg (11.23 lb) and had a length of 104.5cm (41.14 in.) (other sources: 103cm). (go to the link some more information) (also some nice videos on Kazaa lite. look up "german WW2" in video files.

Dude did you try using slightly more counterweight than projectile? Might give a slight kick , but it would give you slightly better range. Less wasted energy out the back. (Yes I may be stating the obvious here... sorry)

Warning: since I havn't tested this, I can't tell you that it is Safe to try with the tube under your arm... stand away from it and test it first, if you ever decide to try. (once again with stating the obvious... i must be tired, anyways 'tis better to be safe than sorry when it comes to playing around with this stuff)

Would a nice piece of Brass plumbing pipe work as a body or is it too "soft"?

(about 2mm thick and 4 cm Diameter i'm guessing)

[Flake2m]

Increasing the range isn't to easy.
If you add more BP propellant you risk blowing up the tube and yourself.
Decreasing the weight of the projectile would work but a lighter projectile wouldn't be as good and err hypothetically would do less damage. Getting a longer barrel would work but the whole thing is going to be heavier. TiaCO3 has already suggestted using extra counterweight. I have no idea how much that would improve the range.

My only other thought is to make the projectile rocket propelled as well as have the initial charge. This would make the projectile more complicated. The easiset way would be to use the standard rocket engines, and use the BP charge to ignite them. Also slower burning BP might increase performance, but you'd have to experiment.

[JoeJablomy]

I just had my first dream in a while, although it was a bad one. My prototype rocket was a piece of 1 3/8" ID x 17" PVC tube that was lying around epoxied onto the cap end of a 20 oz water bottle. I drilled a flash hole because I didn't want to go out and buy electric igniters, and I used very roughly an ounce of some very old smokeless that I have a lot of.
The problem with this was I was afraid it might blow up, being several rifle rounds worth of powder, so I didn't press all the air out of the plastic charge bag and generally didn't do anything that might make it go off any harder than it did, causing it to become another example of my observation that it's much easier to make something that fizzles than something that blows up in your face, and much harder to make it actually work. About the only other lesson I got from this was, don't use some kind of clumpy dirt or dry clay as the countermass; it doesn't pack too well.
The whole thing was kind of a clusterfuck because I scouted the site at night, but at 5:30 when there shouldn't have been many people there, there were fuckloads. The final assembly was very hasty.

Anyway, does anyone else know about smokeless charge design? The major failure of my first dream was that it wasn't sufficiently ignited; pressure couldn't build up very well because of the flash hole. I also don't know how long it took to ignite because I was behind cover and the fuse may have caused much of the smoke I saw.
Electrical ignition would fix this and the flash hole problem at the same time, and might even eliminate the necessity of an ignition booster such as flash powder or a high pressure chamber. I might soon dream about my C/NC igniter ideas.

For further testing when I find a suitable site, I think I’ll make a test fixture of a tube with a flash hole at the middle, and just load identical countermasses in the ends; no trouble to assemble and no projectile to hit some fuck on the head.

As for possible improvements, I think increasing the countermass is a good idea. It shouldn't increase the kick at all; all recoil is transferred to it. Rather, it will take longer to leave the tube and create higher back pressure, increasing the impulse delivered to the projectile. Another way of looking at is it will increase the efficiency by the mass-momentum-energy relationship: the greater mass has lower energy for the same momentum, so if the countermass is bigger than the projectile it will absorb less energy because it must receive the same momentum.

As for a second stage rocket motor, I think it’s a good idea. In the self-contained form I’m using (the rocket tube goes with the projectile and is launched from a ‘bazooka’), the rocket motor would have to be placed far up the inside of the tube, which is sort of an opportunity. I remember reading something by some Brit who did something like this, and found that if he drilled holes in the tube just below the base of the motor it created an ejector effect and made it work better. To be clear, rocket ejectors aren’t generally a great idea on space launch vehicles because the required ducting is heavy, but when it’s already there on the rocket it can’t hurt.
What I would do is I would epoxy the motor into a pvc tube of the right diameter for it and drill holes about ¼” behind the nozzle, and make a wooden plug that’s just long enough to cover the distance between the motor case and the aft edge of the inlet holes with a piece of cannon fuse going through a hole in the middle. The fuse would probably be sealed into the plug with wax (not so that it can’t be lit) and the edges of the plug too. The ‘kick’ charge would go behind this and the countermass behind it. When fired, the kick section would put the rocket well clear of the launcher before the cannon fuse would ignite the sustainer motor, so SWIM would not get burnt rubber and hot HCL vapor in the face.

As for worries about powder charge size and tube strength, I don't think the panzerfausts used very heavy tubes, I think they were actually sheet metal, but I could be wrong. The best thing to do is remotely test it like I will (I mean in my dream).

[Ropik]

I tried the bigger counterweight idea few weeks ago, but with increasing of about 200 gms of sand the range was almost the same, so I leave this idea.

NBK: The range can be improved with lighter warhead and mainly with better propellant, but I don't have any. In the "Poor man's RPG" is mentioned shotgun powder "Red dot". I didn't even hear about this propellant, but I assume that it's NC. Well, maybe someday I will try power this with nitrostarch.

No, I did not make any sights, because the small range.

I think brass tube would be to soft to be safe (actually, this STEEL tube has thicker walls than 2 mm).

BP is housed in short section of paper tube with taped ends. Leads are pulled out the "counterweight" end of tube.

[tiac03]

Your projectile I think is too heavy for the amount of powder you are using.
Your's should weigh about 457.89g for the amount of powder you are using (and that would be if it was the same power as the stuff the germans used) 95g/2900g (propellant/projectile in panzerfaust according to link I posted before) (15g X 2900g)/95g=457.89... (I just put 95/2900=15/X I assume it can be used, simple proportions)
And yes moving to a faster burning powder should be more efficient.

Also is it possible that your projectile leaves the tube before all the powder has burned? (same principle with barrel length, if a barrel is too short the powder is still burning after the projectile has left, therefore wasted energy, and less "push").

[Ropik]

I am pretty sure that all powder burns before actual shot. I just have too crappy BP.
Someday I will try it with bigger charge and blasting box for safety.

[tiac03]

I forgot to ask you in the last post, but how much of a back burn do you get (how much fire/smoke comes out the back) Because I have two video clips about panzerfausts which show quite a bit, As in anyone standing within 5 feet behind it(possibly more) are either burned or smoked out (not to mention hit by what ever counter-weight is being used).

First is a film about the "courageous infantry that destroy tanks." shows 4 different anti tank weapons. an artillery piece looking thing, the bazooka type launcher the germans had "stove Pipe", the panzerfaust, and a shaped charge. Pretty interesting. The other one is just some war footage of german soldiers using the panzershreks (sp.?) and panzerfausts. one thing for sure you saw where the thing came from, the person gets massively smoke-screened.

About 20 grams of powder is what you need i'd say. (although you probably wouldn't see much of a difference. Also I assume you made sure but "make sure that the sand in the projectile doesn't shift around at all". Shifting sand can drop the range of it.(acts as a dampener)

[Ropik]

From the tube comes only smoke, usually there is almost nothing "flashing". But the smoke is quite thick and there is a big amount of it.
The sand was mixed with dextrin, dampened, pressed into can and after drying plastic disc was put on the sand and sealed with heap of hot glue.
I'll try the 20 grams charge.

[Spotter]

He Ropik, cool weapon. Have you more Pictures of your "RPG". Did you have the Book in *.pdf or something else that you can send by eMail. It would be very nice if you can send me more Informations. If you are interessted in any other Books please contact me, i have over 200 Books, and i think a few of them are interresting for you.

MFG Spotter

[charger]

Spotter, are these books in your computer or are they hardcopies? If they are electronic copies, why don't you up them to the ftp for everyone to read?

[Bert]

OT, but perhaps entertaining: Most Valuable Weapon : The RPG (http://www.exile.ru/189/war_nerd.html) Gotta love The War Nerd (http://www.exile.ru/archive/by_author/gary_brecher.html)

[nbk2000]

The Soviets created the RPG for use by Soviet infantry squads against US tanks, APCs and personnel in that big NATO/Warsaw Pact war everybody was dreaming of back in the sixties. The design was an example of beautiful simplicity.

It was a classic of Warsaw-Pact reverse-engineering. Warsaw Pact weapons designers had this attitude that it was a waste of time to design from scratch when you could count on your spies (and the Russians had the best spies in the world back then) to get you the specs on the weapons other countries had spent billions designing.

RTPB "Imitate [bazooka], then innovate [thermobaric warheads for RPG]"

[Ropik]

Spotter, just find the "Poor man's RPG" thread in the Links and literature section. There are many fellows able to send it to you.
I have not Streamload account now and the file is too large to send by regular e-mail.
Sorry.

I have not any additional pictures, this one was digged out of HDD grave in fear of banning. I haven't digital camera now, so I cannot take another photos.
Yes, I'm interested in any books related to subjects discussed on E and W forum. Thanks for offer! :)

[zaibatsu]

Spotter, we don't fucking trade here. You've got 200 books eh? Try uploading them, and if we havent already got them then I'm sure someone will send you the book. Hell, I'll send you ten books. No Fucking Trading

[Spotter]

All my Books have a size of over 1,24 GB. This all uploading??? With a 56k modem??? Tell me how? One or two Books is ok, but more... no, thats expensive and take a lot of time...Sorry. I make a list. Tell me what you want, and i will upload this.

[nbk2000]

The only way your "books" would be over a gigabyte in size is if they were hi-res images of 1,000+ pages each.

If this is the case, then you need to learn how to use image-editing software like photoshop7 (free off the FTP) to reduce them to less than 1/10th of their original size with minimal reduction in readability.

This will make them 100MB in size, and up'loadable by 56K over the course of a day. I know, because I've done it myself like this in the past.

Or, you can just upload the relevant parts of the book, as most books are 80% fluff, and only 20% gold. That brings a book down to 20MB each, all the way down from 1GB. You can upload 20MB in about 2 hours. :)

'Course, it's also entirely probable that you're just saying this as an excuse not to share what you do have, or (more likely) don't have. :mad: This isn't the first time we've heard the "My files are huge and I'm on dial-up" excuse. :rolleyes:

Must be nice to have such a huge harddrive that you can store 250+GB of files. That's a pretty expensive piece of hardware. Seems odd that you couldn't burn them to a DVD or split them amongst CD-R's to make space, meaning you could make copies to send to someone else who COULD upload them.

So what the next excuse?

[Jacks Complete]

The only way your "books" would be over a gigabyte in size is if they were hi-res images of 1,000+ pages each.

Er... I think he means that the total size is 1.24 Gb, not each. 1.24Gb / 200 = 6.4Mb, which is about right.

[Spotter]

Yes. All Books together are 1,24 GB. A few Books a very Small size and other are very big (200MB). I upload a few Books the next Week.

[Spotter]

He Ropik, have you ever used Flashpowder, or only BP? In the "IHBRL" and in the Book "Bazooka, How to build your own" they used this stuff. With this, the range would be better i think. And in first tests with my, a havier Counterwight makes a speeder Warhead. My Warhead is 400g and my Counterwight 1200g. Soft Recoil, but better Range.

[Ropik]

I didn't use flash, because it can explode very easily. The BP only burns in normal circumstances and lifts the warhead off the tube, but flash - when you aren't very careful with it - can make unwanted surprise for you. In IHBRL is this also mentioned - something like "don't confine the flash more than one layer of paper tape, do not tamp it between warhead and counterweight blah blah blah...". I personally don't want in close proximity to my body something able to split and tear three layers of strong PVC pipe(look at the end of the IHBRL book) to shreds.
Your much heavier counterweight can have some effect, I didn't tested my launcher with so big weight difference warhead and countershot. But using three times heavier counterweight to shoot a one pound warhead... I think this puts the weapon on the "cumbersome" category.
I think smokeless powder would be ideal as propellant. I must make some NC and try...
Tests coming soon if I will have time.

[Spotter]

Yes, i think a PVC tube isn´t so good. For Test´s i used a Pipe with 54mm outside and 51mm inside diameter, with a few layers of fiberglass and epoxy. That is 1,5 mm steel and 3 mm Fiberglass between me and the charge. I used no charge holder... so i don´t have a weak point in the tube. The charge is build in at the end of the counterwight and the ignationwires run throu the Gypsum in the counterwight. The Warhead and the Counterwight are made from strong PVC with 50mm outside diameter. The Counterwight is filled with Gypsum. The Warhead is closed with a wooden disc and a thin metalplate. As fins i used cottonstripes and i have testet thin metalstripes. But metalstripes are not ideal. I make more tests and then i write t here. The idea with the Sand is good... i will see the FUCKING Book

[xperk]

I wondered if anyone had tried narrowing the exhaust section of the pipe, thus miniming the need for a counterweight. In theory the delay in the built up pressure of the gasses escaping through the narrow exhaust could work as a counterweight.
In some recoilless designs the round had discs designed to burn/blow away during launch, but helped to build up pressure.

The increased pressure design is probably not suitable for a PVC type launcher.

To my horror this has already been discussed at http://www.roguesci.org/theforum/showthread.php?t=652

[JoeJablomy]

A lot of rocket motors use nozzle plugs to build up enough pressure for stable burning and ensure ignition (also just to seal the motor, I guess).
This would be helpful with smokeless powder due to its pressure sensitivity, although as mentioned it also has the potential to cause a pressure spike.
It seems to me, though, that holding the countermass to the launcher would transfer recoil. I remember seeing that some devices had a lip turned in at the rear of the tube, but I think it was meant as a sort of nozzle. Actually, there is much more force pushing backwards on rocket nozzles than forwards, and they can be blown off; the thrust force is actually applied to the forward bulkhead of the motor. But the forward "bulkhead" in this case, the projectile, is free to move, and if the rear is not, then it will transfer force to the casing/tube and the shooter. So I'm kind of confused by this. Perhaps you might make a unitized round with a solid, stick shaped countermass connected to the projectile by a paper tube with the powder charge. The bursting tube would allow the powder to pressurize.

[chemofun]

I got the pdf version of the poor mans RPG and I am a little confused about the fuze placement. They say to place the fuze inside the body of the projectile which is fine except that the fuze is armed by ejecting the pin one it leaves the muzzle. The problem is, how does the ejector pin get pushed out after leaving the tube if its stuck inside the body of the projectile. I guess a hole could be drilled through both layers of PVC but the precision would have to be pretty good; but for that, what's the point of building a fuze and inserting it inside the projectile as a separate component? Why not just build the fuze mechanism directly into the body of the projectile?

[festergrump]

The problem is, how does the ejector pin get pushed out after leaving the tube if its stuck inside the body of the projectile.
A simple spring loaded pin should suffice. Much like the "spoon" of a hand grenade only flies off the grenade once it leaves the users hand and arms the grenade, the pin could only leave the body of the projectile once it is relieved of the restraint of the launcher tube. (see page 24 of part 1, captioned "Schematic of a Mechanical Point-Impact Non-Delay Inertia Fuze for a HEAT Warhead" for an idea).

Why not just build the fuze mechanism directly into the body of the projectile?
Safety and storage. Many of your expedient primaries don't have a very long shelf-life and are also somewhat unstable, especially after they've aged a bit. (AP is a prime example of this, though I personally would never use AP as a primary in a projectile round, but some may disagree with me. Most here, I believe, would tell you it's a really bad idea due to it's unpredictability and sensitivity).

I would NEVER leave a fuze in a projectile of this nature lying around while armed with a fuze unless it was moments before I sent it to target. Leaving the fuze out while transporting or storing an explosive projectile makes the accidental detonation of the secondary explosive somewhat difficult. Were one of these to go off beside you it'd pretty much end the fight, no? You lose, game over, no restart button.

In fact, I would make the projectile in three seperate stages which could be fitted together just before use. HE warhead, detonator, and fuelled body. I wouldn't even pack in the HE until I was sure I would need such a device, for safety sake, but everything else would be ready to go... primary and secondary would be "made to order"as needed, and the det would only be intact right before I loaded the complete projectile in the tube.