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File: Cartridge Diagram.jpg (26 KB, 474x259)
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The main limiting factor in DIY firearms is the barrel. There is no feasible way to bore a hole through a steel bar with enough precision to be usable without using ludicrously expensive machinery. Instead of trying to produce barrels made to fit existing types of ammunition, it may be more practical to produce ammunition made to fit what can be made from common steel pipe sizes.

The casing could be produced simply by drilling into a short piece of round bar stock. This will leave it with thicker walls than a professionally made casing, but this shouldn’t be an issue. The propellant can either be harvested from existing ammunition or nail gun blanks, or even specially made. (nitrocellulose for propellant and chlorate salts for the primer can both be produced in a home setting with ingredients that will not attract any unwanted attention.) The projectile can be cast from lead, which can be done over an open flame, or can be machined.

It should be fully possible to produce ammunition to the specifications required for what barrels could be constructed at home. The only question is what exactly these designs would be. What are some design considerations that must be taken into account when producing these cartridges?

ITT I am hoping we can develop several standardized designs and construction processes for cartridges and barrels of various sizes.

I am NOT encouraging anyone to do anything that is illegal where they live. This is all purely theoretical, and is only a fun thought experiment.
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>>54152836
>This will leave it with thicker walls than a professionally made casing, but this shouldn’t be an issue.
>what is obturation and gas sealing
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Morse cartridge look it up
The og brass cartridge
Just a brass tube with a base soldered on to it and a percussion cap in said base
Also pa Luty documented making some diy ammo
Also focus of darkness on youtube made his own ammo by taking spent 7.62x39 cases and putting a hilti blanks in the bottom has the same power as a 9x19
Kekistani armorer on youtube and probably here also made a few videos on focusofdarkness ammo style using 38spl and 9x19 cases
It wouldn't be hard to just put blanks Inna standard brass tube size
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As an engineer I'd rather just overbuild the whole system so I could bulk buy factory ammo and have it run on garbage just like my AKs do.
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>>54152836
You still need to drill and rifle a barrel.
Drilling out individual casings from bar stock is one of the dumbest things I've ever heard. Catridge-making in a world where cheap/uniform brass cartridges don't exist was already solved 150+ years ago, you drill a chamber into a piece of steel and then load it from the front.
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>>54152836
The solution to fully homemade guns is acknowledging that worrying about scenarios involving high round counts or even reloading are a meme in any situation you have a chance of getting out of, and embracing muzzle loaders.
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>>54152849
Use a closed bolt action?
O-rings like the old days?

Fuck it, go big and do a recoiless rifle.
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>>54152836
before covid, forster would cut wildcat's for you... chamber reamer and reloading dies both.

I have a couple custom dies/reamers. One in 6mm using a necked down 300WM case (the fireball is magnificent, the barrel life is so-so)
I call it 6mm Donkeypunch.

The other uses a 45-70 case given a 40 degree shoulder and a little bit of a trim--it uses .351 bullets. I call it .35 Boomer.

the camera on my phone has shit the bed so I'm fucked on proving this. But wildcatting is fun. I have no fucking idea what my barrel pressures are, either. I just spitballed it and looked for over-pressure signs in the primers and bolt stickiness.
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>>54152849
This is something I hadn't thought of. I wonder if it would be possible to get the walls thin enough that this would still occur. Maybe if a softer metal is used? I'm also not sure how much of a performance hit there would be from a poorly expanded casing.

>>54153132
Thanks for this, some of these look pretty promising. The guy sticking blanks into existing cartridges reminds me of professor parabellum's ammo designs, although his were basically useless.

>>54153154
If you think you can find a 20" long drill bit that's exactly 7.62mm wide, then go ahead.

>>54153250
I agree that in 99% of situations full auto would be entirely pointless, but muzzle loaders are absolutely obsolete. At the very least, a break action breach loader is needed.
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>>54153448
>I agree that in 99% of situations full auto would be entirely pointless, but muzzle loaders are absolutely obsolete. At the very least, a break action breach loader is needed.
>something that will do the job just fine with less complexity when it comes to building it yourself and keeping it supplied with ammo is obsolete
"Obsolete" doesn't mean what you think it means.
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>>54152836
If you have the tools to turn cartridges then you can make a set of tools for brass cup drawing. All you'd need is a press
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>>54153499
My man, in an age where the average cop or government agent has access to a high capacity autoloading firearm on their hip. And the average gangbanger has one too. Trying to cope with some 1700s muzzleloader ain't it.
If you just want to make a hunting gun, go ahead. But if you're trying to make a firearm that you can relatively match law enforcement or the government, a muzzleloader isn't that.
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>>54153448
Long drills are easy to find, same with the reamers to cut to actual size.
You should maybe spend some time actually learning how shit can be done before making crappy threads.
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>>54153448
>If you think you can find a 20" long drill bit that's exactly 7.62mm wide, then go ahead.

Machinist here, that's actually really simple. no, you won't find that at home depot but any industrial tooling supplier will fix you right up. You can order up custom drill bits of whatever diameter you want. Something like this would probably cost about $150 and take a couple weeks to be delivered. Though that's not the correct procedure to make a decent barrel. You'd drill the hole undersize, then you'd ream it to the final diameter, followed by cutting the rifling.
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>>54152836
People have made 3D printed mandrills that electro etch rifling into a pipe.
It's way easier and cheaper than making your own ammunition from scratch.
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>>54153724
I've seen that before. I'm not sure how reliably it works, but if its half decent then it does solve the problem of rifling for smallish barrels.
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>>54152836
>The main limiting factor in DIY firearms is the barrel. There is no feasible way to bore a hole through a steel bar with enough precision to be usable without using ludicrously expensive machiner
Somebody tell me why people don't just use pipes with diameters that allow you to shove them into each other, do some soldering and boom, barrel.
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>>54152836
muzzleloaders
get a pedersoli double barrel shotgun
a pedersoli sharps 1859
an uberti revolving carbine
and some type of flintlock rifle or musket
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>but if its half decent then it does solve the problem of rifling for smallish barrels.
Don’t expect your first one to turn out worth a shit, but the second should be useable and the fifth good. Assuming you can learn by observation of failure.
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>>54153941
Because barrels are more complicated than that. Also, solder is weak and could even melt.
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>>54153589
a percussion sharps rifle loaded with paper cartridges and having a backup black powder double barrel would do the trick for 1 on 1 engagements
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>>54154007
Sounds like a non-answer.
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>>54154007
>Also, solder is weak and could even melt.
Lol, soldering is how double guns are put together. It's plenty strong, and no it's not going to melt on you. You should stop talking about topics you don't understand well.
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The FGC-9 guide covered making barrels, although I don't know if they actually work or not.
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>>54154007
>Because barrels are more complicated than that.
Why? What's so special about them that makes the method impossible?
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>>54153941
I've seen some favela-tier homemade guns that appear to have been made that way. I don't see the point though, it's not hard to just get thick walled tubing. A hardware store won't have it but industrial steel suppliers certainly do.
It's also not so easy to find pipe sizes that fit nicely inside each other. They tend to either have a large, loose, gap like OP's mom, or they are the exact same nominal size which makes them difficult to assemble.
If you had to do something like that I think the best option would be to get DOM tubing so the ID of one tube exactly matches the OD of the one below it and use heat to slip the larger tube over the smaller one. No solder required.
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>>54154145
>I don't see the point though
>hardware store won't have it but industrial steel suppliers certainly do.
I think you might have answered your own question, anon.
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>>54154177
Nah, not really. Places that sell steel are not hard to find even in small towns. They're often associated with recycling, fasteners (nuts and bolts), or welding/fab shops. Now maybe you have a point in that the average joe might not even know that places like that exist, but I'd assume a metalworking hobbyist or someone who did their homework about where to get parts for their project would know about those places.
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>>54154096
https://en.wikipedia.org/wiki/Solder_fatigue
I would not trust a barrel assembled the way that >>54153941 described.

>>54154127
The inner diameter needs to be pretty precise if you want half decent performance.
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>>54154226
>I would not trust a barrel assembled the way that >>54153941 described.
Why? The solder would be entirely in compression which makes the whole assembly very strong. And as I already mentioned, people have been assembling double-barreled shotguns and rifles for a couple hundred years now, using solder, and those work just fine despite having much less surface area for the solder joint, and the loading being in shear rather than compression. Soldering, or even epoxying, subcaliber barrel sleeves has been well proven as well.
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>>54153897
ECM barreling can be scaled up for any size, you just need a bigger piece of plastic to place the copper wire on
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>>54154550
>you just need a bigger piece of plastic
That's the issue. It may be difficult to manufacture one for a full size rifle barrel. I suppose it could be 3D printed in parts that fit together, but I would be worried about the seam between them creating imperfections in the middle of the barrel. I'm not saying its impossible, it just becomes much less reliable.
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>>54153589
>implying you're stuck with 1700s technology
>implying you can't just add barrels
>implying muzzle loading revolvers don't exist
>implying guns haven't long passed the point of diminishing returns for the situations you'll ever use them, and choice of gun matters more than skill
>implying continuing living after going toe to toe with LE is even a reasonable possibility today
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>>54155318
you're going pretty far past the point of simplicity there.
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>>54155318
Almost everything you talked about was 1700s technology.
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>>54152836
>nail gun blanks
you can already use those raw, glue a projectile on the front and you got yourself a round
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>>54152836
I am interested in home manufacture of primers and powders. How would one deal with sulfur-control laws, what if you had to make your own sulfur.
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>>54153622
>>54153692
Both of you are clueless. Drilling extremely severe aspect ratio holes like rifle bores is a very demanding task, and not something you could at all do with a 20" long twist drill.

The process for drilling holes like that is literally called gundrilling, even when you are not drilling gun bores. It requires specific gundrilling bits and high pressures oil/coolant to flood the bored hole and chips away.

To make truly quality bores you literally need dedicated gundrilling machines that rotate the workpiece and but simultaneously.

You cannot just drill with a twist drill and then ream it for multiple reasons, first you will never ever be able to evacuate the chips in a hole that deep, you are almost guaranteed to break the bit off. It will definitely wander off target, to the point where it's likely to come out the side of the fucking bar before you get to the end.

There's a reason why there is a dedicated process for drilling extremely deep holes, even most commercial gun manufacturers don't make their own barrels because the process is so demanding.
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>>54155465
Nobody uses black powder anymore. Nitrocellulose is stronger and burns clean when made well.
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>>54152836
That's simply not true. There are plenty of ways to create a barrel w/ relatively inexpensive equipment. There are designs out there for rifling machines from the 1700s if not before. You can buy the tooling to do button rifling. Worst case you can make a short barrel and then etch the rifling like some of the people are doing w/ the 3d printed guns.
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>>54155564
jesus christ every time this topic comes up here there are retards who burst in to talk about rifling.

RIFLING IS NOT THE HARD PART, DRILLING IS.

>>54155537
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>>54155545
What about primers
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>>54155580
Drilling it is only going to be hard if you need a long barrel. Huge difference if you're making a SMG or pistol barrel 3 or 4" long vs a rifle w/ 20". Worst case drill it and then true up the outside of the barrel to the bore on a lathe.
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>>54155603
yeah obviously a pistol barrel is doable, which is why homemade guns are almost invariably short barreled smgs.

The posts I replied to were talking about rifle barrels though.

Either way, the problem of making ammunition is still not solved, imo it's effectively impossible to home brew ammunition that's remotely close to a commercial product.

Making ammo is some true heavy industry shit, unlike knocking together a basic smg.
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>>54155390
How so? The main point of complexity in modern firearms is the ammo, and that's the main point OP is interested in solving.

>>54155416
Percussion caps didn't even exist until the 1800s. You can do a ton more today than you could in the 1700s.
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>>54155630
Id like to know more about primers. I know the modern ones are chemically complex but theres some old recipe from 1920 that used a simple gunpowder mix of potassium chlorate, charcoal and sulfur.
Sulfur seems to be relatively hard to make, assuming you just dont have the proper ores or some store to buy it from.
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>>54155723
The chemical aspect to primers isn't the only challenge, making the cup and anvil in any kind of meaningful quantity with a useful degree of precision requires special tooling and equipment. It's just not doable.
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>>54155776
Die and mould kits can be bought and you dont need gigapressure, they cut sheet metal like scissors so theres only one pressure point at a time. Some kits dont need a press you just turn on a screw to close it
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>>54155825
>>54155776
Besides im not interested in the modern stuff yet because it seems out of my depth, i would feel accomplished if i can make a reliable single shot pipe shotgun from raw materials
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>>54155825
Yes I know, but like I said, you are not going to get any decent quantity by doing that, and you are likely also not going to get very repeatable sizes over time. Making precise parts like that via forming is not that simple.


imo, if you want an improvised "gun" that's at least somewhat close to a real gun, you should do large bore air guns.

Air guns with large bores like ~.50"+ with rifle length barrels can approach pistol velocities, meaning you have the form factor of a rifle with pistol-like performance, which is probably way better than any kind of improvised conventional firearm with homemade ammo.

Then all you need is a high pressure air compressor, air tanks, and the ability to cast ~.50" bullets which is simple. The relatively large bores, low pressures, and the ability to cast whatever specific diameter you need means that you could likely much more easily find an off the shelf piece of material with a usable bore size and wall thickness.
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>>54155891
>much more easily find an off the shelf piece of material with a usable bore size and wall thickness.
to use as a barrel, if that wasn't obvious.
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>>54152836
ecm to make barrels.
not that hard.
the real bottle neck is the chemistry for gun powder as the materials are consumables, additionally they are usually monitored or restricted substances. also its actually dangerous making smokeless: i cite the number of factories that have had explosions and other issues in making nitro glycerine and even black powder.
>>bp can be made at home easily however
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>>54155891
Another advantage to this is that there is no need for extraction or ejection so the mechanics are simpler, and the projectiles would be cylindrical instead of tapered like a rifle cartridge, meaning it would be significantly easier to make a working magazine for the ammo.
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>>54155891
>Then all you need is a high pressure air compressor
Anon, do you have any idea how much a high pressure air compressor that works at the pressures big bore airguns operate at costs? You aren't getting there with a normal shop air compressor.
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>>54155970
They are not that uncommon, you can get compressors for things like scuba tanks that are not that expensive and would work.
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>>54155891
If you wanted an even crazier idea I have wondered before if it would be possible to make a liquid fuelled gun, meaning essentially an air gun that you also power with combustion via an injector just like the cylinder of an engine.

I have absolutely no idea if that would be viable but it could potentially allow you to get better performance without needing the extremely complex manufacturing and supply capabilities required for regular cartridge ammo.
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>>54155944
nitrocellulose is not hard to make with perfectly innocent ingredients. I probably can't tell you how on here, but there are youtube videos on it.

chlorates for primers are a bit harder, but if you're competent enough to make the rest of a gun, you'll probably be fine



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