Would it be possible to mount a working minigun onto the saddle of a tyrannosaurid dinosaur?

Question

My modern setting has these humanoids called the Degenerates whose culture draws inspiration from those of Indo-Iranian steppe nomads like the Scythians, Sarmatians and Parthians who fight as mounted riflemen that ride mutated animals donning bulletproof armour. The Degenerates' most skilled warriors are armoured troops called cataphracts wielding heavy weaponry who sometimes ride dinosaurs dubbed Ekhidnades similar in dimensions and looks to the tyrannosaurid Albertosaurus sarcophagus (save for the fact that they have osteoderms, spiny protofeathers, stronger jaws and can expel streams of combustible liquid from their mouths).

I've envisioned that a cataphract would ride their Ekhidnades using a three-person saddle, sitting in the front most seat near the Ekhidnades' neck with while firing a minigun (like a GAU-19 or M134) anchoring onto a swivel mount fixed to the saddle. Said minigun hooks up to car batteries and ammo crates which would provide power and ammunition, somewhere around the Ekhidnades' flanks. Two other cataphracts, would meanwhile, ride shotgun and provide additional firepower with light machine guns, anti-materiel rifles or RPGs as the Ekhidnades rampages about, biting, trampling or immolating anyone unlucky enough to get in its way.

Reference image for the Ekhidnades' armour

Would an saddle mounted mini-gun be useful/practical on such an animal?

Why or why not?

Answer 1

Mount the gun, yes

The M134 has a lightweight variant, which weighs just under 20kg.

I think that's entirely plausible to mount on an animal that size - use leather or some other padding underneath the gun so no metal touches skin, vibrations are minimised, and using leather belts to wrap around and tighten. You'd want a few attachment points at varying angles around the body to avoid chafing or it coming loose during manoeuvres, but the actual mounting I don't see as an issue.

Then the problems begin

None of these are insurmountable, but they will make things complex. You're looking at a training regime measured in years:

• Sound. Have you ever set off a firecracker behind a dinosaurs head before? Me neither. Considerable training will need to be done to make the animal not bolt when its fired.

  • The easiest way of doing this training (just set off loud bangs and zap him when he reacts) will actually make the animal timid and teach something called "Learned Helplessness". You want the animal to assist you in battle, not be an emotional wreck.
  • You probably want to give him earplugs, and start with a low volume recording of gun fire. Get him to do some known task and play the sound. Treat when he doesn't flinch. Then slowly raise the volume.
  • You can't use a deaf breed, or intentionally deafen him, as you need him to respond to commands at a distance. Come here. Run away. Don't eat them they're friendly, etc.

• Recoil. Mini guns put out decent recoil, they just don't appear to recoil when vehicle mounted because they're attached to the mass of the jeep. Unless you plan on drilling into dinosaur bone to mount this thing, that's going to be a lot of force. Some aircraft get so much recoil from their guns they could theoretically get airborne from the gun power alone. In addition to not responding to the sound, the animal needs to be trained to not move when it feels the recoil force pulling back - but still move when the reins are pulled back.

  • This is going to be very hard to train as "keep back steady despite it feeling like I'm correcting you" is pretty abstract. Training assistance dogs for this kind of abstract leveling is possible (people with balance issues can use their big dog as a crutch), so it should he possible in dino, but the training takes a long time.

• Dino movements aren't going to be synchronised with the gun.:

  • Firing a gun from an aircraft needs precise calibration - e.g. timing the firing pin impact such that the bullet passes between strokes of the propeller. Your dino is not going to be in sync with the gun. If dino tries to attack a thing that is attacking him up close, his head will go between it and the gun.
  • If the dino is being attacked by a ranged weapon, the dino will turn to face it, both to charge at it and to minimise himself as a target. That will block your firing solution.
  • The dino's back won't be level while moving, his back will twist as he walks, and move up and down all over the place. Once again, walking in a way which will minimise back movement can be trained, but will take a long time.

It may be easier to domesticate the dino and use him to pull the gun into place on a wagon.

Answer 2

There are a couple of problems.

• Weight. 3 humans are light. OK. But then you are adding machine guns. But ok, your mount is tough. However you are also adding several other weapons and then you are adding armor and a sort of electrical system for the weapons but wait there is more. AMMO!
• Vibrations. The poor animal is not an infantry fighting vehicle. Remember that recoil exists and it has to go somewhere.
• Poor armor. Well it is true that modern tanks are not that worried about their shells exploding when they are hit, because thick armor and all that. However, you are not working with a tank or an armored personal carrier or anything similar. Your rockets for the RPGs are hanging by the side, and your 50 cal rounds are exposed.
• This also complicates things as it is true that even vehicles have certain weak points and engineering can only do so much. But a living creature needs much much more flexible movements, cavalry are all about that to begin with, and so you are looking for a losing trade. Not that nature is bad. But nothing in nature had to evolve to be an mobile fighting platform and the absolute genius of human engineering rules the battlefield.
• Does this model provide better fighting options than existing stuff? Like is it more protective, can you add more stuff to it, like communication equipment... etc, can you easily fix it?
• The easily fixing part again rears its ugly head. If your military vehicle, whatever that is now, has a completely blown tire you just stop, context dependent I know, and change it. Problem solved. But how the heck do you replace the legs of that thing if they get damaged from a mine or enemy shot?
• Unless tanks have magically vanished, they will eat those things for dinner.
• Without tuning down the weapons in the setting those animals will be torn to shreds by enemy fire from a mile away. Modern rounds are very good at killing things that don't have tank armor.
• Also how do they handle guided missiles?
• Anti-infantry artillery and general anti-infantry rounds. They would be very effective against a moving flexible animal because it does not have the same armor in most of its body and unlike tanks or vehicle it has organs everywhere and taking a hit means pain and it can bleed... etc.
• I won’t even mention air superiority.
• This is a quick list and I am sure we can add more stuff to it, especially from actual experts or soldiers.

However, far be it for me to tell you it is a bad idea. I mean, it is a bit of a frame challenge anyway, so I just wanted to raise points that you might already have solved in your own world. It is all about how you set your world.

However I want to add a couple I think actually helps your idea without too much complication.

• Cavalry used special weapons. And your guns are very very powerful for a weapon designed to be all about close range. Historically speaking cavalry, afaik, had shorter rifles to reload on horse back... etc. They had long lances and relied on mobility. Anyway, my point is that for the GAU-19/B your effective firing range is 1,800 m. That is insane for cavalry. Cut down on all aspects of your weapons. The range, the ammo, or even the firing rate. Again you want to get close and fire. Not provide a fighting platform from 2 kilometers away because why is it mounted then? Mounted archers are a thing yes. But that also requires close range by our standards.
• Specially designed ammo pouches. You want to minimize the chance of a lucky hit exploding your ammunition and killing your soldiers. So not only are they are more resilient to damage but they are made so that if a fire catches them they can be quickly expelled away from the animal.
• Shock and awe weapons. Forget about those big weapons and even human siting and firing. Fit the thing with stuff like 556 automatic guns and throw it away inside the enemy lines and fire at all directions. Even stuff like grenades are useful. This is how cavalry fought. The cataphracts closed in and used clubs for stationary fighting. Or they charged with lances.
• You can perhaps breed hearing out of the animal to ignore the insane noise of a modern weapons. Sight is not a problem I think.
• Maybe its natural armor, engineered or just natural, is a highly evolved sort of carapace that is like the stuff on Tyranids from Warhammer 40K. Maybe even remove the pain aspect from most of its body, as we know from history that when elephants got damaged too much they tended to run amok, and destroy their own lines.
• Maybe there is a larger, more specialized version, to be a mobile bio-shield? I don't remember the actual historical things but basically they were like this little construction of different materials that soldiers wheeled from inside to approach the enemy walls without taking too much incoming fire. So perhaps there are three of them, one having armor to safely deliver the other two?
• Other aspects of speed and comfort can be played with. I mean is it fast? Is it fuel efficient? You can mess around with that as you see fit.
• Lastly if our tanks exist in your work they will still rule the grounds battles.

Answer 3

No, they can't carry that much

Let's take stock of just how much you are carrying:

• 3 average human riders = 186kg
• 3 saddles = 21kg
• 1 minigun = 20-63kg (depending on which you go with)
• 1 average car battery = 19kg
• enough ammo for 2 minutes of sustained fire = 140-360kg (depending on which you go with)
• Weapons and ammo for side riders 30-120kg
• additional kit for 3 soidlers (tents, rations, etc.) = 60-150kg
• 1 suit of cataphract style barding + 3 suits of armor for riders = 255kg

That means at a bare minimum you are looking at 731-1174kg. Your diagram shows an animal that is probably about the weight of an Allosaurus (1,500 kilograms). Smaller bipeds like humans and ostriches can just barely carry this % of their body mass, but Ekhidnades have much smaller leg cross sections to body size to begin with than humans or ostrich and the square-cube rule is working against them; so, I will have to say no, they could not carry that much.

Another problem with your Ekhidnades is that they do not appear to be grazing animals, this means that they will need a LOT of food per day. Depending on it's exact diet, it will need about 10-30kg of food per day; so, going on long campaigns will be impossible without leaving lots of room on the creature's back for its own rations.

Possible solutions:

Option A: Remove the side gunners and add pack animals to the group that just carry logistics stuff. This would drop your total weight to as little as ~440kg. While still a heavy encumbrance, it should be much more manageable.

Option B: Use quadrupel herbivorous mounts instead. At this scale, the mounts would closely resemble war elephants which we know could carry 3 well armed and armored riders, full barding, and needed supplies.

Answer 4

Possible, maybe, but not practical.

It would be just as possible to mount a machine gun on this dinosaur as it would be to mount it on an elephant: entirely doable, technologically. However, it wouldn't make sense from a military perspective. If you have machine guns, you have military vehicles. There's a reason why horse cavalry became obsolete after WW1.

Cars, trucks, and tanks don't require massive amounts of food to stay alive; they only need gasoline or diesel fuel when actively being driven. They don't generally don't get killed by a single stray shot from a bog-standard rifle; you'd need to use specialized anti-vehicle weapon against them. If they suffer some minor damage sufficient to mission-kill them like a thrown track or blown tire, that can be corrected with some maintenance time while an animal whose leg has been shattered by a bullet or explosive might need to be put down since it can never be replaced.

Answer 5

Cyborg dinosaur!

The gun is built into the dinosaur.

Modern cars are drive-by-wire for smog. You tell the computer to shift, and it shifts. That way the computer isn't surprised by the sudden event, and is able to pre-adjust fuel injection etc.

Our dinosaur can't either. The dinosaur must fire the gun. The gun is part of its body. needs to choose to fire: so it will expect the side-effects: recoil, noise, etc. You must then train it well.

You might have to raise the dinosaur from a baby with ever increasing gun weights, several basic sizes and shim weights added every day, so the gun feels like part of its body and it's used to moving with it.

It isn't knocked off balance by the recoil because it braced in anticipation of it. It isn't shocked by the noise because it made the noise. (A dog isn't surprised by its own barking). It moves its head well out of the firing arc because it learned in training it got electric shocks if it didn't.

The dinosaur must aim coarsely, but a computer with servos will do the fine correction.

The dinosaur knows when it's Winchester because it can feel the weight of the empty ammo box, and can warn the human of low ammo. It knows how to help humans change the mag, or stand and heel correctly so the autoloader on the ammo truck can do the same.

Answer 6

It is undoubtedly possible. And, as other posters have noted, with a lot of training and a few adaptions, it might even be possible to actually use it.

The issue though is one of practicality. There is a reason why cavalry are little used, in the second half of the 20th century horses were only used for transport. In the age of artillery and machine guns they are big, vulnerable targets. Your dinosaur even more so.

As a bit of Hollywood showmanship, it's terrific, and I think we'd all like to see that movie. But, as with the handheld minigun in Predator ...let's not get too bogged down in the realism thing.

Answer 7

Different Ideas for Different Mounts:

The ideas in these answers aren't bad, but if you love the idea of a giant bipedal dinosaur as a mount for your troopers, keep an open mind. First, you want you critters to be cheap and easily controlled, stable in a fight, breathing fire, and carrying a big, long ranged rapid fire weapon. I will handwave HOW you get dinosaurs, and assume they just are. I am imagining a tropical, forested environment where pop-up concentrated ambush attacks would be most effective. Bipedal herbivores would be able to feed up and down such trees.

First, the biology will do whatever you want, so I would say go with a herbivore rather than a predator. The predator still can work, but herbivores are likely to be more abundant in nature, are cheaper to feed, an are usually more endurance-based (I know, generalizing). These creatures could even be repurposed agricultural animals, depending on the conditions. Skip fire-breathing, and mount flame-throwers on the beasts. It requires a lot less energy for the critter and weapons can be easily swapped. You might even be able to balance the weight of a flame thrower with a mini-gun.

Rather than very small-brained critters somehow following complex tasks, have an animal who is pithed, and the skilled rider manipulates controls to induce the animal to follow instructions. This can be as simple as a needle inserted into the brain or spinal chord, or as complex as a bundle of implanted wires stimulating behaviors (or anything in between). Your people can then swap out dead mounts easily by simply rounding up wild dinos and pithing them, rather than requiring extensive breeding, training, etc. but they still could breed them for a steady supply.

With a dino that is easily kept calm, the machine gun is relatively simple. Side-mounted might work better, possibly with a slot for a pin on each side so the dino isn't always "left" or "right." The gun would then be best mounted sideways centrally, with a "pilot" at the front near the head, gunner in the middle, and weapon-crewman opposite the gun, balancing weight.

The advantages of your dinos over vehicles will be silence, height, and range (as they can eat plants in a forest, not refuel). I envision a single dino or a small squad popping up on an enemy patrol, opening up from longish-range and pouring vast quantities of fire on the enemy for a very brief time. They are tall, and can shoot over low vegetation, and your pilot can lift the head up to see over obstacles with a commanding view. Then they would melt away silently into the underbrush.

Alternately, flamethrower-equipped units could sneak up on enemy positions, blazing, and the first thing enemies would hear is the unholy scream of flamethrowers (it's an evil noise, if you aren't familiar).