Someone told me recently that the capability to create plastic guns a la In the Line of Fire is now here. I thought that he was mistaken. Is this now possible?
Thanks,
Rob
Were they perhaps talking about the use of 3-d printing to make many of the parts for a firearm? Here is Forbes trying out an AR-15, where the lower has been formed out of polymer via 3-d printing.
A major sticking point is that you can’t, to the best of my knowledge, do this sort of thing for either the chamber or the barrel, as even modern composites can’t handle the stresses. Those are still required to be made out of metal, usually a high strength steel. Whether you could make those items out of ceramic, I don’t know.
Im not familiar with In the Line of Fire. There are many firearms made primarily with “plastic” (Im sure the manufacturers have a better name for it like polymers or something.) The various models made by Glock springs to mind but there are others.
Is there something specific about the firearms from the movie that made them fictional?
Probably not for something like a rifle round, but would it be possible for sub-sonic pistol ammunition?
Maximum chamber pressurefor a .223 rifle round is 55,000 PSI, while for a .38 pistol round it’s only 14,500. I would guess you could hand-load something quite a bit less powerful that would be lethal at close range.
The firearm in the movie was completely homemade out of plastic resin so that it was completely undetectable by metal detectors. It wasn’t made with a lot of plastic parts but some important metal ones like a real modern gun. It was made completely out of plastic with no metal parts at all, which is very difficult (if not impossible) to do with current technology.
There is a lot of controversy over whether that gun design would actually fire, though even its proponents admit that the gun would probably not survive being used multiple times as was done in the movie.
Here are pictures of the gun in question:
There’s not much point in a plastic gun unless you also have plastic shells and plastic bullets - at least that would be my guess since I assume the whole point of plastic is to evade detection. In that case, it’s a lot easier to disguise a normal object such as a pen or flashlight. These can be modified to work as a simple zip gun and involve little more than adding a spring, firing pin and cocking mechanism - all of which can either be hidden, disguised or disassembled to be unrecognizable. The problem is that bullet is still going to be metal and still look very much like a bullet.
Spoiler for a 20 year old movie ahead:
In The Line of Fire
John Malkovich’s character hides a couple of rounds in a hollow keychain. Puts the keys in the little tray before the metal detector, goes through no problem, and then gets his keys with hidden bullets back.
As the video shows, even the printed lower receiver is only good for a couple of shots before it falls apart. I think it is prone to jamming, too.
The real problem for many tasks that 3D printers are posited for is that 3D printed materials (either polymers or sintered metals) are not suitable. Also, you cannot mix materials, and you cannot finish (polish/smooth) the parts.
The US military has put together fabrication units (in a 40ft container, I think) for operating bases, with a combination of tools (3D printing, multi axis CNC tools, electronics toolsets etc) to allow in-theatre fabrication of parts and repairs - as time goes by, suppliers will be required to provide appropriate data files for these facilities so that troops will not be hampered by a shortage of spare parts that can be provided from the fabrication unit. And it will not be long before there is a combined multi-axis CNC/multi-material 3D printer that can print and finish complex parts - the technologies are substantially the same - a CNC tool head could just as easily be a polymer/sintered metal print head. With the addition of some robotic or manual assembly, the sky will be the limit.
Si
The whole point behind the gun in the movie is that the gun was very, very simple. It is indeed possible to make such a gun out of plastic, or wood, or anything else. People used to make cannons out of tree stumps, after all. This is not something that has just happened, either. People have been making very simple improvised guns ever since guns were first invented.
Now, making a modern semi-automatic weapon is an entirely different matter. All automatic weapons require a minimum amount of metal in the springs to allow the weapon to operate. Therefore, there is no such thing as an automatic weapon that can pass through a metal detector, (thanks Die Hard). Because the exploding gases inside the barrel are what operate the autoloading mechanism, the parts must be able to withstand a certain amount of stress.
As we saw with the 3d printed lower receiver, any gun can successfully fire at least once. Getting it to do so repeatedly is the real trick.
Yes, it is possible. It is also very illegal under 1988’s Undetectable Firearms Act which prohibits such weapons.
I was just thinking about the Metal Storm concept of stacked rounds that are triggered electronically. That weapon is just composed of tubes of these rounds.
It should theoretically be possible to build something small that would hold 3 or 4 .22 cal. rounds and fire them electronically in rapid sequence. The whole thing could be the size of laser pointer or large ball point / fountain pen like a Mont blanc or similar.
The assassin’s weapon had metal parts (including the bullets) which were hidden in the rabbit’s foot keyholder. I remember the charging mechanism was in the form of rubber bands instead of springs.
You just have to look up the development of the Glock pistols (and the Steyr-Manlicher assault rifle) to see what breakthroughs there were in giving firearms a metal diet, replaced by plastic. Lighter weight (but bulkier), greater reliability for a lot of the bearing parts.