What about a short shotgun? I think there are some shotguns with fiberglass barrels to make them lighter. A shotgun would produce less pressure, so you might be able to get away without metal.
Also, I think there are rifles with electronic firing systems; I’m thinking I saw one in a Remington catalog. It used special ammo, but I’m not sure how it worked, or if something like that would be useful in our case.
[QUOTE=T_SQUARE]
Also, I think there are rifles with electronic firing systems; I’m thinking I saw one in a Remington catalog. It used special ammo, but I’m not sure how it worked, or if something like that would be useful in our case.
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Wouldn’t you need metal for batteries, circuit components and conductors?
[QUOTE=Stranger On A Train]
Springs are another issue entirely; there just isn’t really a good mechanical replacement for metal coil or cantilever springs, and I’m not sure how you’d make a working gun without springs of some kind. Rubber and plastic just don’t have enough energy storage density to replace steel for these applications.
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Given that ceramic is a good insulator, you could forego a standard firing cap, and instead have an internal chamber with a lit flame and a “trap door” to let it set off the weapon. Or, for instance, a set of match heads on a wheel which strike over the surface as they are turned down into the combustion chamber or such. You might not be able to achieve a firing rate as high as a regular weapon, but you would be able to fire a round of projectiles over a still decent rate.
As another alternate, you could use pressurised air as a replacement for a spring, if you had multiple chambers, one for each round.
[QUOTE=Szlater]
Wouldn’t you need metal for batteries, circuit components and conductors?
[/QUOTE]
Probably, but I have no idea how much. A little watch battery should do it, I’m not sure if it would be enough to set off the alarms. We still have the bullet itself to deal with; I don’t think the electronics would add much given the metal bullet, primer, and casing.
[QUOTE=sweeteviljesus]
If you get away from conventional ammo and have a non-reloadable gun which is fired using electrical squibs, you could get away from that problem. I believe that is how the troika pistol worked (it was supposed to have steel barrel liners though). That is assuming the troika was even real.
FWIW,
Rob
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Well, I guess it’s possible to make design similar to MetalStorm, only instead of barrel(s) you had ceramic block with drilled holes. Rather radical departure from conventional firearm design, but could work. Short lifetime wouldn’t hurt much, since ceramic block of barrel(s) would be preloaded and used only once. For additional strength barrel-holes could be lined with these short-fiber composites that **Stranger **mentioned. Block of electronic could be detachable and multi-use.
You could, I believe, make a functioning Derringer-type (or Howdah Pistol-type) firearm using ceramics and plastics, but your weak point is going to be ammunition- cartridges are brass, with metal primers, and metal-jacketed projectiles.
Your best bet would be an Arquebus; with a ceramic barrel, wooden stock, plastic serpentine, and firing a ceramic or plastic ball using black powder and the application of a match to a touchhole. The problem is that it would be unwieldy, inaccurate, and you’d only get one shot, unless you wanted to carry a fibreglass ramrod, animal-horn powder-horn, and spare musketballs, at which point you’ve really crossed into the “Being silly” side of this thought exercise.
[QUOTE=astro]
I was reading an item about ceramic gun barrels, and wondered if any ceramics are tough enough that you could make an entire gun out of ceramic materials.The ammo can be standard ammo in this case.
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The answer is NO. Ceramics are great for surviving compression tests.
Ceramics fail in tension or when subjected to sundden shock conditions as in a firearm.
[QUOTE=minor7flat5]
Not sure what space age polymer msmith537 is referring to, but this made me think about carbon fiber.
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I was thinking about whatever John Malcovich used in In The Line of Fire.
[QUOTE=spingears]
The answer is NO. Ceramics are great for surviving compression tests.
Ceramics fail in tension or when subjected to sundden shock conditions as in a firearm.
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Don’t they use ceramics for armor plating?
[QUOTE=msmith537]
(…)
Don’t they use ceramics for armor plating?
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Yes, but the idea is that plate is destroyed when hit and soak up energy of the bullet in the process. Ceramic armor plates are designed to be easily replaceable.
[QUOTE=msmith537]
I was thinking about whatever John Malcovich used in In The Line of Fire.
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That appeared to be some kind of unreinforced polymer resin. Even if he was firing a fairly low powered round (it’s been years since I’ve seen the movie, but I recall he concealed the rounds inside of a hollowed rabbit’s foot, so presumably they were something like a .32 S&W Long) the peak pressure would far exceed the capability of any polymer, so that it just another incidence of Hollywood magic.
[QUOTE=msmith537]
Don’t they use ceramics for armor plating?
[/QUOTE]
Chobham composite armor and the like are used on most modern tanks, sandwiched between plates of high strength steel (called rolled homogeneous armor). The primary purpose of this type of construction is to protect against HEAT (high explosive armor piercing), APDS (armor piercing discarding sabot), and HESH (high explosive squash head), . With HEAT and APDS rounds, the primary method of penetration is by creating a jet of superheated plasma or vaporized metal that cuts a path for the actual penetrator; Chobham retards this by fracturing the sandwiched glass layer upon contact, creating a layer of shattered glass that absorbs the heat, preventing burn through and creating a semi-fluid layer that distributes the shock of the penetrator. HESH rounds work differently; instead of attempting to penetrate the armor they squash on contact and create a shock wavefront through the armor with the intent to cause lethal shrapnel via spallation (fragments on the interior surface breaking off and injuring the crew). In this case, the glass layer shatters, both damping and distributing the shock wave, and creating a hollow cavity that causes the wave to be reflected. Because the inner plate is much thinner than a single thickness of RHA would be, it deforms more easily and doesn’t spallate at much. Either way, protection from these types of rounds is dependent upon the ceramic matrix layer shattering, and effectiveness of the armor is somewhat reduced after multiple impacts (although less so than predicted; there are reports of M1A1 tanks taking multiple hits from T-64 and T-72 tanks in Gulf War I without substantial damage).
It goes without saying that you wouldn’t want a ceramic gun to shatter upon use. Some kind of fiber reinforced ceramic matrix might work, provided you could get the moduli of the matrix and fibers somewhere near each other, but it would require some seriously high tech material deposition technology.
Stranger
[QUOTE=Stranger On A Train]
That appeared to be some kind of unreinforced polymer resin. Even if he was firing a fairly low powered round (it’s been years since I’ve seen the movie, but I recall he concealed the rounds inside of a hollowed rabbit’s foot, so presumably they were something like a .32 S&W Long) the peak pressure would far exceed the capability of any polymer, so that it just another incidence of Hollywood magic.
Chobham composite armor and the like are used on most modern tanks, sandwiched between plates of high strength steel (called rolled homogeneous armor). The primary purpose of this type of construction is to protect against HEAT (high explosive armor piercing), APDS (armor piercing discarding sabot), and HESH (high explosive squash head), . With HEAT and APDS rounds, the primary method of penetration is by creating a jet of superheated plasma or vaporized metal that cuts a path for the actual penetrator; Chobham retards this by fracturing the sandwiched glass layer upon contact, creating a layer of shattered glass that absorbs the heat, preventing burn through and creating a semi-fluid layer that distributes the shock of the penetrator. HESH rounds work differently; instead of attempting to penetrate the armor they squash on contact and create a shock wavefront through the armor with the intent to cause lethal shrapnel via spallation (fragments on the interior surface breaking off and injuring the crew). In this case, the glass layer shatters, both damping and distributing the shock wave, and creating a hollow cavity that causes the wave to be reflected. Because the inner plate is much thinner than a single thickness of RHA would be, it deforms more easily and doesn’t spallate at much. Either way, protection from these types of rounds is dependent upon the ceramic matrix layer shattering, and effectiveness of the armor is somewhat reduced after multiple impacts (although less so than predicted; there are reports of M1A1 tanks taking multiple hits from T-64 and T-72 tanks in Gulf War I without substantial damage).
It goes without saying that you wouldn’t want a ceramic gun to shatter upon use. Some kind of fiber reinforced ceramic matrix might work, provided you could get the moduli of the matrix and fibers somewhere near each other, but it would require some seriously high tech material deposition technology.
Stranger
[/QUOTE]
Penetration of the armor plate for both HEAT and APDS ammunition is by plastic deformation and hydrodynamic flow of the target material. There is no burning associated with the actual penetration. After armor effects include overpressure, thermal effects from a HEAT jet, heated metal fragments (you pressure metal enough to flow and there is lots of heat), and pyrophoric splinters from depleted uranium. Layman’s terms; the metal just pushes the armor or target material out of the way. APDS rounds are like a shooting an arrow through a target, HEAT rounds are like a compressed gas or water jet punching a hole in a target.
The impact area of both types weapons on a target exhibits extreme heating as a result of the material flow.
The long rod penetrator of the APDS round concentrates enormous pressure on a small area. Typical dimensions are a length to diameter ration exceeding 25 to 1. High velocity, density, and use of sabots to reduce/prevent spin are the other parts of the energy equation. Penetrator materials are generally tungsten carbide steel or depleted uranium. HEAT rounds “google shaped charges” create the concentrated pressure via an engineered explosive train, form of the main explosive charge, and optimized stand-off distance. A HEAT warhead doesn’t even have to be moving to penetrate a target. The Wiki entry notes significant performance attributes to liner material. Not to diminish the contribution, no liner is actually required to produce the shaped charge effect.
A previous post on springs: Composite fiber springs replace metal lever or coil springs in automotive applications. See Corvette suspension as one specific example.
Couldn’t you resurrect the GyroJet concept, executed in ceramic, carbon fiber, and polymer? The barrel of the original was often described as “flimsy”, so it seems to me that even minor attention to strength would give you a weapon that would slip by metal detectors. Keep the shape away from the standard pistol shape, and you might be able to let it get scanned, too.
Tris