Needlessly long names aside, how would this weapon work?

Made from scratch with junk scavenged from a 21st century world, post nuclear apocalypse. Assume nothing was specifically preserved, only the knowledge of our protagonist(yours).

I want a projectile weapon that uses anything you can fit into it(I avoid saying "gun" because I doubt you can make one good enough for this, and even if you can, at that point get a better gun).

Think the"Junk Jet" from Fallout, only a bit more reasonable.

No fancy autoloader system needed here.

If possible, I also want to be able to retrofit it into a nice melee weapon.

All that said, using what is availible, how can ouur hero convince this set of spare parts to output the junk he inputs wuth enough force to be a weapon?


6 Answers 6


I want a projectile weapon that uses anything you can fit into it

A historical example of such a thing might be a blunderbuss... a sort of flintlock ancestor of the shotgun which sometimes was loaded with stones and bits of wood and any other crud that could be rammed down the barrel. Problem is that a) jamming rubbish into your gun damaged it and b) random bits of junk tend to be quite unaerodynamic which sharply limits your range and likely reduces their ability to damage a target as well.

The Junk Jet (and its predecessor, the Rock-It Launcher) aren't afflicted with real world physics, which is why arbitrary items can become deadly projectiles. Unless you want to radically soften your setting's physics and bring in the rule or cool and/or funny, you can't make a practical weapon this way.


What's wrong with a sling

A sling is a projectile weapon typically used to throw a blunt projectile such as a stone, clay, or lead "sling-bullet". It is also known as the shepherd's sling. Someone who specializes in using slings is called a slinger.

A sling has a small cradle or pouch in the middle of two cords (retention cords). A projectile is placed in the pouch. There is a loop on the end of one side of the retention cords. The middle finger (although some slings have a wrist loop) is placed through a loop on the end of one cord, and a knot, or tab, at the end of the other cord is placed between the thumb and forefinger. The sling is swung in an arc, and the knot/tab released at a precise moment. This action releases the projectile to fly to the target. The sling is much more than merely an extension of a human arm. By its double-pendulum kinetics, the sling (or woomera) enables stones (or spears) to be thrown much further than they could be by hand alone.

The sling is inexpensive and easy to build

or an atlatl?

A spear-thrower, spear-throwing lever or atlatl (pronounced /ˈætlætəl/2 or /ˈɑːtlɑːtəl/;2 Nahuatl ahtlatl [ˈaʔt͡ɬat͡ɬ]) is a tool that uses leverage to achieve greater velocity in dart or javelin-throwing, and includes a bearing surface which allows the user to store energy during the throw.

It may consist of a shaft with a cup or a spur at the end that supports and propels the butt of the spear. It's usually about as long as the user's arm or forearm. The user holds the spear-thrower in one hand, gripping near the end farthest from the cup. The user puts the butt end of the spear, or dart, in the cup, or grabs the spur with the end of the spear. The spear is much longer than the thrower. The user holds the spear parallel to the spear-thrower and going in the other direction. The user can hold the spear, with the index and thumb, with the same hand as the thrower, with the other fingers. The user reaches back with the spear pointed at the target. Then they make an overhand throwing motion with the thrower while letting go of the spear with the fingers.

The dart is thrown by the action of the upper arm and wrist. The throwing arm together with the atlatl acts as a lever. The spear-thrower is a low-mass, fast-moving extension of the throwing arm, increasing the length of the lever. This extra length allows the thrower to impart force to the dart over a longer distance, thus imparting more energy and higher speeds.

The sling in particular is great because you don't need to worry about taking a lot of ammunition with you, as long as you can find stones around you.

  • 1
    $\begingroup$ Worth noting that sling work best with projectiles of the right size and weight. Sling-wielding Roman auxiliaries cast their own lead bullets, because that was most effective. Atlatl dart manufacture is also less simple than it looks. It is easier than fletching an arrow, but it isn't "turn any stick into a deadly spear", by any stretch of the imagination. $\endgroup$ Commented Feb 27, 2022 at 11:05
  • $\begingroup$ My only problem with the sling was how hard it was to use, but this altalt weapon I like. My only complaint with that is spears are hard to carry multiple of. $\endgroup$
    – KombatAce
    Commented Feb 27, 2022 at 18:56
  • $\begingroup$ @KombatAce atlatl darts are intermediate in size between arrows and spears. They're also lighter as the shaft is there to provide appropriate balance and drag and a launching spring, but it doesn't have to be stiff enough to be driven into someone by hand. $\endgroup$ Commented Feb 28, 2022 at 9:14

Old old OOOOOLLLLDDDD school: hands.

Nearly everybody has at least one.

They can project nearly anything as a weapon. With some practice you can use a wide variety of stuff as ammunition. Just some examples: pebbles, broken furniture, dead animals, live animals, broken guns, working guns with no ammunition, rotten eggs (for that improvised chemical device effect), buckets of sand, etc. etc. etc.

They can be used quite quietly/stealthily in case you need to avoid spooking the quarry, or its mates.

They can be used to carry home your target if it is edible.

They add little to your encumbrance in case you must walk a long distance.

From small-furry-animal, to that annoying guy with a stick, to an apple just out of reach on a tree, to the last can of peas on the top shelf, hand-thrown projectiles can be, well, handy.


Since you have a hopeful mention of guns I am assuming the character will have the means to produce and maintain the weapon at least initially, but lacks the material to build ammunition ("all I have is enough metal for the gun" or something similar). But does have the means to create gunpowder or other explosives to fire the projectiles he does find.

The humble but reliable Pump-Action shotgun.

As long as you have a proper sabot to carry the projectiles in you can fire pretty much anything that fits the bore. A 12 gauge is about 18,5mm size and even a shaped stone projectile(s) can be effective.

Just like a sling or other lower-tech weapon the aerodynamics of the projectile will determine the accuracy, but even if you use basic nails as ammunition your gun can be effective. Just not out to a large range. Solid slugs made from a variety of materials would also be effective, although without machine tooling the accuracy will be low, meaning that you will have to rely on ball-ammunition rather than aerodynamic projectiles.

Pump-action shotguns are more lenient and forgiving than shotguns that use other means of cycling the load, making them more reliable and sturdy. Which is what you want if you might not be able to service your weapon properly over extended periods of time.

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    $\begingroup$ I am not a boomstickologist, but I do wonder how easy it would be to maintain a pump-action under post-nuclear-apocalypse conditions. The mechanism is pretty robust, but it is still a mechanism. There's something reassuringly simple about break-barrel shotguns and bolt-action rifles. $\endgroup$ Commented Feb 27, 2022 at 13:58
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    $\begingroup$ @StarfishPrime while yes a fire-arm like that would be hard to maintain long-term in apocaliptic conditions, this does not seem to factor into the question as much. Yes if it were so hard to maintain that after one battle or a week you need specialist equipment to maintain it it would not be a good choice. But we got free reign for even gun-type weapons to be produced by the main character, so I would assume that occasional maintenance and perhaps spare parts/barrels can be obtained or produced every now and then. $\endgroup$
    – Demigan
    Commented Feb 27, 2022 at 18:37
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    $\begingroup$ Yeah, its never very clear what "post apocalyptic" really means, and the "Junk Jet" comparison sounds like it isn't a bleak and hopeless future the OP is thinking of. But I was genuinely curious as to how inconveniently mechanical a pump-mechanism is. Could a blacksmith fabricate new parts for it, for example? Does it require watchmaker-like skills and tolerances? Its a tickly sort of subject to ask about in many parts of the world, though. $\endgroup$ Commented Feb 27, 2022 at 19:17
  • $\begingroup$ @StarfishPrime I dont have all the facts but as far as I know the tolerances of a smoothbore pump-action dont need to be as high as rifled guns. You might even be able to hollow out the barrel as damage occurs to keep the inside smooth enough, increasing the bore until the barrel walls get too thin (this was actually done with some forms of artillery). But no I cant tell you the exact tolerances or how difficult it might be to do with hand machine tools, which is likely the max you can expect in this world. Aside from the barrel though I think it can all be build by a blacksmith is my GUESS. $\endgroup$
    – Demigan
    Commented Feb 27, 2022 at 19:59
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    $\begingroup$ I might ask a question on this very subject. $\endgroup$ Commented Feb 27, 2022 at 20:10

Hollow barrel crossbow.

enter image description here

I invented this just now, for you. The bow is a leaf spring from a truck. The string is a steel cable. You whittled the stock out of a canoe paddle. On firing, the string pushes a cylinder down the barrel. Anything you put in the barrel comes back out, fast.

Because regular crossbows are great until you can't find any bolts. Guns are fine until you can't find the right ammo. Dynamite powered blunderbusses are fine... well, they are fine. But the hollow barrel crossbow will shoot anything you can fit in the barrel including that stick of dynamite you were saving for the blunderbuss.

Suffice it to say that this thing will accept whatever you want to put in it. Its working name is thus quite short but not fit for printing here.

Original crossbow source: https://www.youtube.com/watch?v=7Jfn5j9fadw

  • 1
    $\begingroup$ I absolutely love this. I am eternally grateful to you, intelectual stranger. I don't know what a leaf spring is, but I will look it up $\endgroup$
    – KombatAce
    Commented Feb 27, 2022 at 21:03
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    $\begingroup$ What holds the top of the tube on? Also this will be horribly weak, you will be lucky to fatally injure a dog sized animal much less a human. $\endgroup$
    – John
    Commented Feb 27, 2022 at 21:22
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    $\begingroup$ @John I am glad you asked. The slit along each side of the pipe to admit the string does not run the entire length of the pipe. The slit extends as far as the string can move. Behind that maximum and in front of the minimum string extent it is unbroken pipe. These uncut areas are what holds the top to the bottom. As regards horribly weak, I am surprised! Do you think truck springs are so puny? $\endgroup$
    – Willk
    Commented Feb 27, 2022 at 21:26
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    $\begingroup$ The flipside of not being horribly weak - and I agree the leaf spring of a truck is pretty strong - is that the force required to draw the steel wire "string" will require a pulley system to re-cock, making it very slow firing. It will require a more substantial stock than the average canoe paddle given the forces involved. Finally, the mass of the following cylinder and its friction with the pipe will reduce the usable output force significantly. +1 anyway $\endgroup$ Commented Feb 27, 2022 at 21:49
  • $\begingroup$ @KerrAvon2055 - agreed on all eminently practical improvements. The difference between an architect and a general contractor: the contractor has to make the dreamed scheme work in real life. $\endgroup$
    – Willk
    Commented Feb 28, 2022 at 0:53

A Blunderbuss

The precursor to the shotgun, they were meant for this kind of thing. The general idea is as follows:

  1. Take a wide, un-rifled tube and securely cap one end. The other end should preferably widen in a bell shape, but it isn't necessary.

  2. Bore a small hole near the capped end.

  3. Stick some saltpeter-soaked cord through the hole you bored in the previous step.

  4. Put some gunpowder in it.

  5. Put some rocks, nails, and other small hard things in.

  6. Tamp it down (carefully, so that you don't accidentally set off the powder.)

  7. Point it at the target and light the cord.

They leave something to be desired when it comes to range and accuracy, but that's not really relevant in the kind combat they're used for.


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