Oh yes, personal powered armors, such as MJOLNIR, are a staple of sci-fi. A sci-fi that disguises itself as fantasy needs to have some for the knights!
But, there is one thing I don't want to let it do, that is increasing encumbrance. If powered armor allows people to wield and shoot a Barret M82 like it was nothing, the whole point of finally letting armor catch up to firepower is lost.
So, powered armor can increase punching strength but won't allow you to carry that weight. Why?
You can't
The whole point of power armour is to carry more and carrying more means carrying bigger guns and if you had power armour, people would make bigger guns for them to carry.
Weapons soldiers use is limited by their ability to carry it around. Bigger weapons require a mobile weapon platform (ie wheels). Power armour is just another mobile weapon platform. It's stronger so can carry more and has more mass thus can handle more recoil from bigger weapons.
Any reason you come up with will have to be wishy washy such as a mega death cannon doesn't look as cool as a giant ass sword
There is no physical reason for power armour not to have bigger guns and it would defy logic not to give them bigger guns.
$Strength \propto \frac{1}{Speed}$
Also known as "Speed versus Torque".
Power armour loaded to slightly more than the typical soldier's kit allows you to sprint at high speeds without getting tired, leap 10 feet into the air, and punch like a charging bull.
Power armour can also let you carry a metric ton of weight (e.g. a 1979 Volkswagen Beetle). But, not both at the same time.
Think about it this way: a car can zoom along at 150mph, or it can drag a heavy trailer up a hill. It can't drag a heavy trailer up a hill at 150mph. The former requires a High Gear setting (high speed, low torque), the latter requires a Low Gear setting (low speed, high torque)
So too with your Power Armour. If the techs back at base have set it up for pure strength, then you have pure strength. The Force behind your punch is going to be on par with a freight train - if you can hit something. You'll be moving slowly enough that most people can dodge: $Power = \frac {Force*Distance}{Time}$. You can push really hard, and apply tons of pressure, but not fast enough to be worthwhile as a punch.
Similarly, you could probably use a Howitzer like a rifle - but, you can't aim it fast enough to track most moving targets close-up. And, at range, you might as well just put it down and use it normally.
It's not feasible
If powered armor allows people to wield and shoot a Barret M82 like it was nothing, the whole point of finally letting armor catch up to firepower is lost.
There is a quote: "If it works, it's already obsolete". It's inevitable that people would try to use find something to counteract the counteraction. For example, There is methods to block adblockers that blocks ad that blocks adblockers.
Unless...
The old solution to the problem just isn't available. Maybe at some point the size of the weapon would need to grow in size exponentially to have enough power to destroy the armor that gets carrying capacity linearly.
For example (all numbers completely imaginary): In the beginning in that case a armour would be destroyed by a 5kg gun, but allow for carrying 30kg. Later it would need a 10kg gun to be damaged, but only allow for 35kg extra capacity. Eventually these two points meets at, for example 100kg.The next iteration of armor would need a 200kg weapon to be damaged, but only allow for 110kg carrying capacity.
The guns would still get absurdly more powerful, but not enough to actually be useful against an opponent with a similar armor.
Or maybe the armor just happens to have some other pseudo-magical boons that counteract the weapons.
FORCE FIELDS:
All that armor is nice, but it's real virtue is in being a surface that conducts energy for personal energy fields that foil all those heavy weapons. These fields conform to the user's armor suit, and they are most vulnerable to contact with other armor, since the fields interact. So lasers refract, plasma scatters, projectile weapons are deflected, or bounce off, or need to hit incredibly hard, yet a fellow suited warrior with a conductive melee weapon attached to their suit can cut through it.
If the field is somehow psychic, even better - drone weapons and robots can't use them, and psychic power doesn't need a portable nuclear reactor.
That's not to say all those weapons don't work, or are ineffective. I don't think you can stop bigger guns, but they would need to be MUCH bigger to compete with force fields. The real goal isn't to take away the cool toys, but to bring back the good old fun ones - fists, swords, axes, etc.
The power provided by the armour is equal to the power needed to move said armour. In this case wearer still can't transport anything heavy, but they can deliver a good punch - high mass means high kinetic energy.
This idea was partially used in Fallout 1, where weight if the armour is higher than the bonus it provides - https://fallout.fandom.com/wiki/Power_armor_(Fallout). Though, strength stat increase meant being able to hold heavy weapons.
While some answers have delved into the mechanics of powered armour (speed vs torque, the effects on joints and so on), there are other consideratons which might come into play.
A suit that lets you carry this makes more sense
OK, we're going to squeeze in through the basement window and then find the tunnel entrance....
I'll see your armour and raise you a missile
Or, you could always issue some of these instead
JOINTS!
If you carry more weight, when you try to jump, the added weight will destroy the complex wired teflon joints.
If you try to move with more weight, the effective range is reduced, after all, the fuel cells can only provide this much juice.
Shooting a barret is done stationary. Leaping with 30 kgs more, will stress the knee and ankle joinst past the safe limit. Could be a moment of tension in your story.
If I carry a bigger gun but discard the rations.. maybe I can make it before I die of dehidration.
As an alternative: conventional weapons have simply changed.
Around the time of world war II all factions asked themselves the question of what caliber their weapons would need to be, and all 3 came around to the same conclusions for each caliber and their use. This because each caliber had a purpose in how powerful they needed to be at different ranges.
With the introduction of power armor we can also assume that metamaterials are introduced. If you can synthesize the strongest spidersilk available to spiders you can make incredible armor protection, and this is just one layer of your power armor. Graphene doped products, Diameme(1), converting the bullet impact into pressure inside a layer etc could all help make these armors extremely resiliant while weapons might still be prohibatively expensive. A railgun for example has problems at the end of the barrel where the forces expelling the projectile blast bits of the rail away with each shot, needing replacement soon.
The end result is that the conventional weapon is still an explosive charge meant to launch a bullet, but with a larger base caliber to wear down power armor and chip pieces away, bruising the internal structure until finally the armor or occupant fails. So your soldiers do carry a machinegun version of an M82, but are still less able to kill their opponents.
It's mostly the lack of real world experience of most game designers that causes what you see in games, which is why I seldom play them. Given my experience as a paramilitary contractor, i cringe at the sight on how wrong they get it. in one movie with soldiers in Science fiction, i cringed as I watched them do over 20 things that you just never do on the field.
I personally believe that manned platforms like power armor simply wouldn't be made, and instead humanoid war droids would be deployed instead. The biggest solution to MJOLNIR killing a normal human is to make the platform unmanned from the get go, and mass produce those. a battledroid can be mass produced whereas a human takes two decades to mature, and is irreplaceable. when a human dies, you're never getting him back---not even with cloning.
and to answer the question, humans wouldn't carry that weight, because they would never have the need to. Just send in your MJOLNIR based killers robots against the covenant and keep your virtually never ending flow of reinforcements coming against the covenant. superior technology or not, with an endless flow of reinforcements, the covenant would soon find their holy war untenable if not outright unwinnable in a period of a year to 17 months by my estimates. And it's how it would actually be.
generally, stories like halo usually have the Spartans to give something the audience could relate to, but it's far from how such a conflict would actually be fought. The UNSC would quickly phase out manned assets and start a crash program to replace them with unmanned versions the first battle things go south, and start investing in unmanned drones and warships like there is no tomorrow. Although the Spartan IIs would be in the picture, they would become the main bodies of drones based on their suits, and operate from semi-unmanned warships.
you halo fans may call me out on the above, but it's how in real life it'd go in all likelihood. in spite of of being outclassed in technology, the UNSC, once they go the unmanned route would crush the covenant under the weight of endless numbers.
as a matter of fact, that's how the Red army and the armies of the allies defeated the Axis powers in WWII: Numbers.
and with Halo and other games, it's just a story, and somebody's opinion. It's an opinion based best guess of what somebody thinks will work.
Because the weight limit is still the person
It's kind of funny you mention MJOLNIR armor in your question, as HALO lore very specifically ties down the armor to SPARTAN soldiers because the armor literally will kill a normal human if they attempt to wear it. You can increase the power of armor, sure, but ultimately, there's a human inside that armor, which means that all the armor's weight is focused on the human. So, even if it can have a hydraulic punch that can dent a foot of steel, it still can't pick up significant weights or handle massive recoil without putting too much stress on the human wearing it.
It will probably still allow for the casual use of the M82 sniper rifle, but fortunately futuristic super-alloys is also a staple of sci-fi, so you can make the armor out of that and explain that they are now completely bulletproof.
In another question it was asked why power armour wasn't feasible. It's because firepower is incredibly high, making power armour too expensive and easily damaged to be viable.
To offset this, the power armour might have added several layers of protection. All the weight added to it does make a "normal" movement difficult to stop and thus incredibly powerful. A punch is something you don't want happening to you or equipment you own. Downside is that the motors are taxed to the max thanks to the weight. Any additional weight starts slowing it down, making only light and normal weapons feasible. If heavier weapons are carried, the armour gets so slow It's impractical or simply stops to function. Finally, the armour is still strong despite being at it's maximum power thanksto the weight. Possibly in the field the armour often accidentally crushes the weapons when the soldiers are in tense situations and they squeeze their weapons. This makes heavy weapons too risky to wield as they present a more hefty investment. Add to this that soldiers are often more panicky if the armour moves slow because of a heavy weapon they are more likely to tense up so hard the weapon breaks.
Up-scaling the weapon (including its weight, recoil and ammo load etc) means ups-scaling your power armor in the process - including its cost an complexity. You also rapidly reach the point where the weapon system being 'carried' by the power armor can just as easily be mounted in a normal fighting vehicle.
This means your armor has to have about the same mass as a fighting vehicle fitted with the same weapon but the vehicle will almost certainly have with a lower profile and be easier too conceal.
At the same time (if not before) you reach the point where your armor ceases to be 'worn' by the wearer and is instead 'crewed' by an operator or operators. Unless you are talking one shot 'fire and forget' systems most large weapons need a team to operate effectively for any length of time. This means you are not 'wearing' armor anymore but instead 'operating' a two legged fighting machine. And in almost all situations such a machine would be inferior to a wheeled or tracked opponent.
Recoil is the problem.
Weapons soldiers use are limited not only by the mass of the weapon, but also its recoil. See the XM109, an experimental version of the M82 which weighs only 33 lbs, but has an impractical amount of recoil - no matter how strong or weak you are, firing the weapon will just about knock you over. A strong but light suit of power armor would allow soldiers to carry huge weapons, but not actually fire them, since they still do not have sufficient mass to resist the recoil.
Weapons with large recoil must be mounted to a heavy chassis, or else the weapon will shoot itself backwards when fired - firing a tank cannon that's not mounted to something with the mass of a tank is a bad idea.
You don't really need power armour to have a man portable, shootable 50 caliber. The gepard lynx does a great job at shorter ranges no power armour needed.
Lets assume you wanted to prevent real overkill - like a 30mm autocannon round. There's probably a few engineering constraints to consider, what static and dynamic forces involved.
Armour is static, and dosen't need you to suddenly handle a large impulsive force. A gun would. Even a way to improve punching strength would have lesser dynamic forces than a gun.
If your power armor is as hard to penetrate as a tank, then you need a gun as powerful as a tank's main gun to penetrate it. The problem is that this often means annihilating the entire area that your target is standing in as well. But in modern warfare, infantry is not used for annihilating a target, it is made for taking and holding key infrastructure. If you start running around with 130mm cannons inside of a command bunker or on the bridge of a starship, neither side will end the conflict in possession of the thing they wanted to take and hold, because the collateral damage would take out the thing you are fighting over to begin with.
This means your weapon designers will need to design weapons that not only can penetrate an inch of carbon nanofiber composite armor plating, but can do it without destroying everything around your target. This is where high-tech melee weapons will come into play. If your power armor has a claw that can exert thousands of tons of crushing force, or a fusion powered plasma blade that can superheat anything it touches to a 10,000K in a fraction of a second, then you start seeing weapons that will kill through the armor without having to worry about a single missed shot bringing the whole ceiling down on your head. Power armor infantry may still have crazy powerful cannons for when they get stuck fighting in the open, but once they have a roof over thier heads, it's time to "fix bayonetts" or whatever your future equivalent of that is.
Thorne's answer that wielding heavier weaponry is unavoidable is correct. However, there can still be diminished returns.
So, powered armor can increase punching strength but won't allow you to carry that weight. Why?
A very important distinction: I infer your interest is in limiting the damage output of the weapon, not its weight. Your question is built on the assumption that the only limiting factor in weapon output is what a soldier can carry, but you're subtly also relying on that increase in weight and power output scaling equally.
Your answer is found in making that weight/damage increase not scale evenly.
If increasing a weapon's damage output by a factor of X increases its weight by an even bigger factor of Y, that leads to needing a significantly stronger power armor to wield it, which in turn leads to a significant increase in defense (bigger than the damage increase of the weapon).
The logic is as follows.
- I make a weapon that does X times more damage
- This weapon now weighs Y times more (where X < Y)
- We develop armor that is Y times stronger so it can wield this new weapon
- This new armor can therefore wear armor plates that are Y times stronger
- This armor's defense is Y times stronger, and since X < Y, the new weapon is less effective (against the new armor) than the old weapon was (against the old armor)
And the cycle repeats. If the weapon weight increase is not linear but exponential (for a linear damage increase in weapon damage), you can't even repeat this cycle too often because of the ludicrously strong armor you'd be required to develop just to wear it.
And that is, after all, the effect you're going for.
So while the improved damage output of weapon still increases, it doesn't increase enough to actually overcome the defense increase of the improved power armor itself.
To justify this, you simply need a civilization with better armoring skill than gunsmithing skill. Or you can rely on basic chemistry whereby the material used for armor gives you more bang for your buck than the material used for your guns.
Carry bigger guns? Why not. You have the extra capacity. You will be slow but sometimes that's worthwhile.
Fire bigger guns? Now that's another question. A bigger gun requires more stability while firing. A human-sized platform (ie. your power armor) can only provide similar stability to a normal soldier.
One real advantage is that you can ensure that the armor assists the soldier in providing better stability, but then you get something similar to what well-trained elite soldiers can do on their own. Still better, because you now have green grunts firing on par with elite squads.
Changing posture helps with stability, but again, the same for naked and assisted soldiers. But maybe, your armor has some stability-enhancing accessories, like a third leg that unfolds from your back on demand.
Still the size of the weapons you can fire reliably won't be affected much, even though you can
If we are talking about man-portable but not man-fired weapons, like portable mortars, you sure can go bigger if needed, but usually the extra capacity is better used for extra ammunition.
Reduce Accuracy
You can always say powered armor that allows great strength will reduce accuracy.
You can prevent them from being useful. Invent a high-tech reactive armor that completely negates conventional weapons. Next you need a high-tech gun that can get around said armor, but doesn't work near big hunks of metal (e.g. power armor).
The weakness of any power system is often it's controlling structure. I know there are other answers about weapon recoil, but no-one's mentioned the substantial noise and vibration that a heavy weapon tends to bring with it.
All you need is for the control systems of said power armour to be unable to resist the vibration - this would make the armour technically able to bear a heavy weapon, but rendered useless and immobile as soon as the weapon is fired. As a hint, if the armour system is a self-balancing humanoid (ie two legs, or anything else that requires a substantial balance) it will require a sensitive electric gyroscope to track it's orientation. (Admittedly you'd need a bit of license on this, as I know there are now some quite strong gyroscope systems used in military jets that can deal with vibrations of supersonic flight).
If this was the case, it would create an obvious weakness when the armour sustains a hit (unless it's being used against chemical, biological or incendiary warfare I suppose). The simple answer to that is to have flexible damping/insulation between the 'main frame' and the exoskeleton - flexible enough to absorb the shock of a hit, but also to render a heavy weapon useless if mounted on it either through inaccuracy or overall torsional weakness of the shock-absorbing system.
At the moment, two of the largest armies in the world are contesting a region called Galwan Valley.
It might surprise you to learn that neither sides' troops are carrying firearms.
Despite both sides being nuclear powers, neither wishes this fight to escalate. There have been conflicts, and there have been casualties (people beaten to death with fists).
Limited conflicts, where one side voluntarily shows restraint, aren't new. It could be that politically use of powered armor to "keep our boys safe", but simultaneously limiting what they can do offensively is palatable to whoever is making the decisions.
Doctrine, design, procurement, and training can have a long lead time. So, if a prior administration commissioned the power suit as a restrained-conflict weapon, there's now institutional inertia keeping it that way, even if the current situation is different.
