I wouldn’t be surprised if there are very hard plastics or ceramics that could be used to make firearms. The bad guy in the Clint Eastwood/Secret Service movie In the Line of Fire made a small, derringer-type pistol out of wood and plastic, but hey, that’s Hollywood for ya.
“Can you fashion some sort of rudimentary lathe, Captain…?”
Big problem is tensile strength - by themselves plastics have no chance. Ceramics are a funny beast, insofar as the term covers many very high-tech materials, ones that have absolutely nothing common with everyday fired ceramic objects. Titanium nitride for instance is a ceramic. If you had enough money you could probably make a sintered TiN gun barrel.
I have seen carbon fibre wound barrels. The tensile strength of carbon fibre easily meets the specification. However its unfortunate habit of failing with essentially no warning yield makes it a worry. I don’t know how well it would survive the temperature and chemical attack requirements. Brittleness is always a worry with many of these materials.
those carbon fiber wrapped barrels still have a steel sleeve at the center to take the rifling.
It’s also worth noting that to a certain extent, guns are made the way they are because steel is a very convenient material for them, despite having some annoying characteristics (e.g. corrosion, fatigue, etc.).
If a bunch of skilled engineers & metallurgists who were also gun nuts sat down and did a from-scratch design constrained only by a need to avoid Fe content, it’s possible that they could come up with a design that sidestepped a lot of the difficulties inherent in building a non-ferrous ‘conventional’ firearm. E.g. if you designed the thing to have a lot of amount of spring room and long levers, you might be able to substitute steel springs for polymer elastics in compression or tension.
That’s true, but as I remember it he’d planned on it firing only one or two shots, which is all a gun like that would last for. The bullets had to be concealed separately, inside a rabbit’s foot keychain, to get them past security.
Most of the real-life focus is on trying to make non-metallic guns to avoid metal detectors. If all you had to do was avoid the use of steel there would be a lot more options that no one has ever bothered to pursue.
I don’t see why the use of other metals can’t produce something that works just like conventional guns. I’d expect them to be somewhat larger and heavier, and wear faster, but other metals and alloys can do everything that steel can do. Bronze should be suitable for the barrel, although other alloys wouldn’t need to be as heavy. Polygonal rifling should be more durable than grooves in softer metals. Aluminum springs can replace steel, though they would need to be larger, but I think there are other metals that could work even better. Bullets could simply use lead, which would reduce barrel wear. Just removing iron shouldn’t be that difficult. Going with no metal at all would be much more of a problem.
You could make gas springs (commonly used to assist lifting hatch-backs on cars). The rods are normally stainless steel, but there is no reason they have to be. In fact some of the newer spring powered air-rifles are going to gas springs.
Way back in 1995…
I recall seeing a movie some years ago (it may have been In the Line of Fire, but I’m not sure) in which a guy made a small double-barreled gun out of wood and rubber bands. He hid 2 bullets in a rabbit’s foot key chain, back in the days when you put your keys and change in a little tray and just passed it around the metal detector, and thus got through airport security with a gun and ammo.
This was clearly not a documentary, but could such a contraption be possible if you planned to use it only once?
Sure. It takes very little to make a zipgun that would work within the confined space of an airplane. No metal at all would be required. The bullets could be made of ceramic, or just rocks, and the shell could be plastic. Since you’re in such a confined space you easily make a miniature crossbow that can be disassembled into innocent looking pieces that won’t be detected by metal detectors at all. So after you kill a couple of people, what to do you do next?
I dunno. Didn’t say I was planning on doing it.
Anyway, I checked and it was indeed In the Line of Fire, and John Malkovich was planning to use his wooden gun to shoot the President. I don’t recall what his escape plan was, or if he even had one, or was on a suicide mission.