To clarify, in full Cronenberg fashion, I would like to know if there is any biological material that does or can exist that is magnetic and could work in a Gauss Rifle.

Using a Gauss Rifle or Coil gun would require ferromagnetic material, but alternatively using a rail gun would not. I would also like to specify that below is meant to be a hand held weapon, however this question is about the projectile and not the rifle itself.

What I'm trying to do is to make a rifle that fires bullets that are made of some biological material that is both magnetic enough to fired out of a Gauss Rifle (link describing what that is exactly earlier) and is suitable material to actually make a bullet out of. The early concept was a rifle that "grows" bullets inside it's chamber using a combination of genetic engineering technology and stem cells. The bullet would be hardened on the outside and take the shape of an ordinary modern bullet, perhaps the size of a .22 LR round, but be filled on the inside with some kind of fast acting flesh eating bacteria that would make any wound fatal within a few minutes assuming the bacteria was not killed somehow. However, upon further thought I realized that wearing body armor of any kind would effectively stop these from happening since the bullets would be hollow point in order to shatter inside the target releasing the bacteria. The idea then came to me that accelerating such a bullet to an appropriate speed, and perhaps changing the design slightly, would allow the bio-bullet (as I call them) to pierce the armor. Maybe a bullet designed such that when the wedge applies pressure, or it meats (pun) the resistance to spin created by flesh in a person, it widens or breaks? I can't say I know too much about the physics behind projectile weapons so I can only have ideas, not speak to their scientific accuracy. I've got my heart set on the biological/cronenberg theme, so I'm hoping there is a way to make it work!!

This edit is to explain that while this question ask if a living animal could evolve to have a railgun as a natural weapon, I am specifically asking about making a projectile outthat can be fired out of a traditional rail gun or coil gun (man made magnets and metal and all that jazz). This is different because it does not have to do with evolution but rather biological engineering, and concerns only the projectile and not the rifle in its entirety.

Additional edit: As can be read in this paper I found, it might seem that genetically altering flesh eating bacteria to take on the additional properties of "Magnetotaxies" (as they are referred to in the paper). These are bacterium that swim along magnetic field lines toward a particular polarity, and additionally dead bacterium become orientated relative to the magnetic polarity they were observed to follow, even after the poles switched. Combine these properties with the properties of a flesh eating bacterium, and the first problem of this projectile has been solved.

The remaining problem is the delivery of these bacterium to the target via a hardened, hollow cartridge. The material that comes to mind would be bone, since the magnetic properties of the bacterium would allow for the propulsion of the bullet and thus the cartridge itself does not need to be magnetized. However, the hollow point design is rendered ineffective by body armor and by the fact that these bacteria would be propelled out of the nose of a hollow point bullet by the magnets rather than propelling the bullet itself. a hollow point too small for a bacterium to pass through would render the purpose of the hollow point design, to shatter inside its target, pointless. How might one design a projectile to break upon entering a a human target without using hollow point?

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    $\begingroup$ Possible duplicate of Could elephants evolve into living railguns? $\endgroup$ Apr 19, 2018 at 1:37
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    $\begingroup$ And how would it dissipate the heat generated? $\endgroup$
    – RonJohn
    Apr 19, 2018 at 1:42
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    $\begingroup$ @RonJohn as you can see by the edit made, I am not asking how to design a railgun or coilgun out of biological material, but rather a projectile that one would fire. Thus, I am not concerned with the workings of the rifle, just a biological material which could be used to make a magnetic projectile. $\endgroup$
    – user49634
    Apr 19, 2018 at 1:46
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    $\begingroup$ "the reason Iron itself cannot be used is because the body does not produce it". Well, the body doesn't produce anything. **Everything comes from what we eat and breathe. $\endgroup$
    – RonJohn
    Apr 19, 2018 at 2:22
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    $\begingroup$ @RonJohn I recognize you as the person in many of my previous posts and questions who does everything possible to undermine my questions to the point of undermining the idea behind fictitious world building. Since you seem to be ignoring the core request, despite the fact that I already solved this part on my own, I will point out that iron is an inorganic material, and the constraints of the question call for an organic or biological material. Again, I already solved this part of the question, all thats left is how to design a projectile to break in its target without hollow point. $\endgroup$
    – user49634
    Apr 19, 2018 at 2:39

3 Answers 3


Yes, with a caveat, there are several known usable ferro-magnetic biological materials, most are relatively high in iron. However, they are all microscopic. In most cases the whole reason they exist is for the detection of magnetic fields.

Although there is the option of biological material that serves instead as the raw material that can be refined into what you want, this is already a field of current research: Biological Routes to Metal Alloy Ferromagnetic Nanostructures. Biology is good a creating nano-scale structures, so it is under investigation for creating magnetic nanofibers.


I'm not an expert on railguns, but as far as I know, the fired projectile doesn't need to be magnetic itself, it just needs to be "affected" by magnetic fields. Like, for example: simple iron. Not magnetic by itself, but will be attracted to the magnet. The magnetic field needed to move the projectile is generated by the gun itself. So any ferrous compound would do as long as it has enough iron in it.

edit: When i write magnetic, i mean having it's own magnetic field, being a magnet itself.

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    $\begingroup$ Also, to add: a projectile can be either armor piercing or fragmenting. If it is hard enough to break through armor, it won't fracture inside the body. If it's brittle enough to fracture on impact into flesh, it won't pierce body armor. However, you don't need to conpletely enclose the poison/bacteria completely in the bullet. You can have some deep grooves in the side (but not the nose) and place those in that. From there, it will be in contact with the flesh/intestines of the victim, once it enters it's body. $\endgroup$
    – joecro
    Apr 19, 2018 at 11:53
  • $\begingroup$ For coil guns, the projectile either needs to be ferromagnetic but not necessarily magnetized (in fact, having aligned magnetic fields might even be worse), or needs to be carried by a ferromagnetic sabot. Both devices (rail guns, coil guns) work by electromagnetism. (BTW, a coil gun is just a very special case of the humble solenoid. In fact, if you switch it correctly, every solenoid is a coil gun.) I'm actually not 100% sure if a rail gun round needs to be ferromagnetic, or just conductive. $\endgroup$
    – Matthew
    Apr 12, 2020 at 16:46

With biological and genetic engineering, the possibilities can be almost endless... Even when working with hard substances, there is the possibility of infusing magnetic metal into the material. The biggest advantage would be that you can work with structures in the bullet that are microscopic in size.

An alternative to bone could be chitin or keratin, both of which can not only be fabricated to include magnetic materials, but can also be made somewhat porous.

Where the big advantage of your bio-bullet comes in, is that the bullet is not fabricated - it is grown. In that regard, you can think outside of the box as it were and make use of features that are otherwise impossible in fabricated bullets.

This way, you have loads of other possibilities than a hollow-point or syringe-like design.

As the purpose of the bullet would be to administer a type of bacterium, there can be a way to make the bullet shell somewhat porous without sacrificing too much structural integrity.

In order to break through armor, mainly the tip has to be hard and sturdy - the bacterium "pocket" could then be located somewhat to the rear of the bullet. Thousands to millions of slanted, forward-facing holes could be arranged in a ring around the tip - enabling the force of deceleration to act in administering the bacteria, much like in a syringe bullet or dart. In short, you would not need the bullet to shatter in this case, but only to decelerate enough to remain in the body of the target.


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