Full body bullet resistant armour

Question

The "people" wearing this are 10 times stronger than humans and have near unlimited muscular endurance so weight is of little (but not no) concern.

Their ballistic and gun technology is as advanced compared to the modern day as the modern day compared to WW2.

By advanced I mean:

• RPM (Rounds per minute)
• FPS (Feet per second)
• Ammunition Capacity
• Ability to mass produce

The majority of the population who are regular humans (10 billion) wear US Marine Corps style armour when in the military.

• These are the "enemies" who will need to be unable to penetrate the armour.

However, the other people (will refer to them henceforth as "the OP") wear very flexible (negligible effect on movement compared to combat gear) armour that is:

• Nigh on indestructible even under heavy fire from armour piercing rounds out of a Barrett 50 BMG.

Do not worry about vehicular armaments as for reasons I cannot fit in a few lines those are not used in combat.

I need to know if there is a theoretical way to make this armour possible.

Ideally it should cover every part of the body.

Answer 1

Consider the energy in the bullet. When the bullet stops, where does the energy go? It could go into heating or breaking a piece of metal that it hits. Or the bullet could hit nothing, and its kinetic energy turn into heating of the bullet itself. That is my proposal:

Induction armor.

The principle will be the same as that used in induction brakes

A conductive surface moving past a stationary magnet will have circular electric currents called eddy currents induced in it by the magnetic field, as described by Faraday's law of induction. By Lenz's law, the circulating currents will create their own magnetic field which opposes the field of the magnet. Thus the moving conductor will experience a drag force from the magnet that opposes its motion, proportional to its velocity. The kinetic energy of the moving object is dissipated as heat generated by the current flowing through the electrical resistance of the conductor.

The possibility of stopping a bullet with eddy currents was discussed on the physics stack: https://physics.stackexchange.com/questions/238332/can-we-stop-moving-bullets-by-eddy-currents

Instead of a metal train rail moving past an electromagnet, here the electromagnetic field is produced by the armor and the bullet moves into it. The armor is composed of futuretech room temperature superconducting coils spread around the body. A small electromagnetic field is maintained at all times on each coil, and this magnetic field projects a small distance out past the body. https://physics.stackexchange.com/questions/478/is-it-possible-to-project-a-magnetic-field-at-a-location-in-space

When a bullet made of conductive material enters one of the fields it generates its own field opposing it, which is instantly detectable. A capacitor is discharged into the region of the armor generating the penetrated magnetic field. This in turn increases the eddy current of the incoming bullet. The strength of the field is proportional to the speed of the bullet, and so it is slowed most when moving fast, and less when moving slow. Red hot bullets moving slow might make it to the armor and gently bounce off.

You can make your room tech superconductor out of whatever you find plausible (I like metallic hydrogen mined from Jupiter), or you might decide it is unneccesary and make your electromagnets out of carbon fiber.

Benefits:

1: Individual cells can power up when they need to repel a bullet and stay in ready mode the rest of the time and so it conserves power.

2: The armor is not used up or damaged when it repels bullets.

3: Because it is powered it does not need to be as bulky as armor which uses mass to deflect bullets.

4: It is total scifi, but plausible scifi.

5: Magnetic fields this strong might have other effects which would be fun in the story.

Drawbacks:

1: If you are really in a storm of bullets, you might discharge all your capacitors and then you are toast.

2: You might run out of batteries or otherwise damage your power source.

3: Purely nonconductive projectiles (e.g. ceramic, rubber) will not be deflected at all.

4: A very slowly moving red hot bullet might gently bounce off the back of your helmeted head and fall down your collar.

Answer 2

Their ballistic and gun technology is as advanced compared to the modern day as the modern day compared to WW2.

The funny thing is, gun technology has plateaued in recent decades. We're at a point of refining designs that are known to work. Here's a few speculative things that never quite off the ground which might be in your world.

• Flechettes
• Caseless ammo
• Duplex rounds or otherwise firing two bullets so rapidly there's no barrel climb.
• Reflex sights
• Aim assist

This is all centered around increasing hit probability and increasing the amount of ammunition one can carry.

RPM (Rounds per minute), FPS (Feet per second), Energy (Dispersed to target), Ammunition Capacity, Ability to mass produce

Two of these things are not like the others in terms of "advanced": energy and RPM.

The energy of your standard military rifle round peaked in WW2 and then dropped when everybody switched to intermediate rounds. Full rifle rounds like .30-06 or 7.62x54 deliver 3000+ J and are designed to still be effective at 2000 meters, but were found to be unnecessarily heavy and difficult to control in burst or automatic fire. Most shooting was found to be done at 300 meters or less, so everyone switched to lighter and more controllable intermediate cartridges like 5.56 NATO and 5.45x39.

Similarly RPM has generally dropped to allow for more controllable fire. Many battle rifles dropped their fully automatic settings and instead are single-shot or burst fire.

While we're certainly capable of producing monstrous rounds with high rates of fire, your average soldier probably won't be carrying them unless there's a good reason, like an arms race with advanced armor.

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...armour that is nigh on indestructible even under heavy fire from armour piercing rounds out of a Barrett 50 BMG

Assuming this is the goal, 50 BMG packs quite a punch: 18,000 J. No current body armor will stop it, the scale ends at Type IV designed to stop armor piercing .30-06 with 4000 J. 50 BMG will go through 20mm of steel at normal combat ranges. Furthermore, designing body armor to stop one round is one thing. Designing body armor to stop a hail of rounds is another thing.

The surface area of your average adult human male is about $2 m^2$. At 20 mm thick that's 40 L of steel. At about 8kg/L that's about 320 kg of steel. If these folks are 10 times stronger, that's the equivalent of 32 kg. Heavy, but very good for full body armor. And that's just the upper end using steel. You can use whatever handwavium you like to further reduce the weight.

Small armor plates which overlap ingeniously, connected with smart, flexible handwavium, will provide flexibility yet never leave a gap.

As discussed above, if your average soldier has to hump around and fire 50 BMG their effectiveness and hit rate will drop dramatically. 50 BMG is already enormous with a tremendous kick. Soldiers won't be running around firing 50 BMG. It has to be either a specialty weapon, such as an anti-material sniper, or vehicle mounted. Carrying and firing anything much larger or hotter gets ridiculous.

Instead of ratcheting up the calibers and energy they'll probably switch to 20mm HEAT rounds and man-portable anti-tank weapons such as Javelin but shrunk down. While they'll be able to penetrate the armor, this will still greatly reduce the effectiveness of the average soldier as now they get a few slow shots whereas before they could carry hundreds of rounds. The armor will still have done its job.

Answer 3

I don't think a full-body armor is possible. The reason I say that is you have to move, and anything that moves is weaker than something that doesn't. An analogy: in medieval times if you could get your sword between plates or inside the elbow/knee, you'd wound the other combatant.