Could missiles replace guns at the personal level?

Question

Could small guided missiles become a practical replacement for conventional guns at the personal level?

I was thinking about the evolution of aerial warfare, and the nature of how missiles have almost entirely replaced guns for fighters. It occurred to me that the same basic concept could almost work at the personal level if the technology could be made small enough on a practical level. The traditional problem with aerial warfare was that traditional gunnery is hard and thus missiles became more effective over time to the point at which they utterly dominated as they allowed longer ranged engagements.

Because the comparison is going to be made, the Vietnam War did not actually show that fighters need guns, it showed that pilots needed training on how to use missiles properly. While the US Air Force was insistent that the problem was that the F-4 did not have guns, the US Navy realized that the problem was insufficient training and created the Fighter Weapons School instead. This doctrine has survived to the present, in which the US Navy didn't seem to care if their version of the F-35 had an internal cannon. I would assume the same issue would be true here as well. Guided missiles for infantry require rather different tactics than guns, and trying to use them like simple guided bullets would likely make them seem ineffective in a similar way.

This also has a possible origin, within the nature of combat onboard spacecraft or space stations. While shooting guns onboard spacecraft is certainly possible even with the downsides, the problem is one of how to hurt enemies without destroying vital components of the ship. Powered armor makes this worse, because you now need weapons strong enough to punch through the armor without also punching rather large holes in things you'd rather not destroy like components of the life support system or possibly the hull of the ship. Guided missiles might be the solution, in which you're much less likely to wreck the ship because you're not firing nearly as many shots and they're vastly more likely to hit the intended target.

One of two problems is also almost certainly going to be the case, both of which might favor missiles. Either you will be firing weapons in microgravity, or you're dealing with a strong Coriolis effect caused by spin gravity. In the former case missiles would have value because they mostly lack recoil depending on the launcher, while in the latter they would compensate for the Coriolis effect by being a guided projectile rather than requiring that the user aim in an extremely counterintuitive fashion depending on the environment.

Once you have dedicated guided missiles for this environment, they could also become practical for other situations as well if they are more cost effective for a given situation. If it takes at least several thousand rounds of ammunition to take out a single enemy given the difficulty of aiming and need for suppressive fire, while it only takes a handful of missiles to accomplish the same effect, the missiles could be more cost effective even if they are vastly more expensive.

Is this possible?

Answer 1

No

Having thrown out a bold, blanket assertion, let's look at why.

People have various instinctive thoughts when they think about gun combat, especially when an image of a personal guided missile is mentioned. They may think about the classic sniper going for a headshot at 600 metres (or more). They may think about the trenches of WWI. They may think about Neo and Agent Smith squaring off in a subway station in The Matrix.

What the uninitiated don't tend to think about is that the average engagement range in a domestic / police gunfight is 3 yards. (I prefer metric, but the FBI work in archaic units and it's their statistic.) Note that this is the average, which means that while there are longer ranges involved in some engagements - obviously some are at hundreds of metres - they are so vastly outnumbered by the engagements at ranges of even less than 3 yards that the average is dragged down.

The simple fact is that at 3 yards a projectile that can steer itself in flight is completely unnecessary, all that is required is the ability to point the barrel within a few degrees of where it needs to be. A missile that could turn enough to turn a miss into a hit at 3 yards would be so slow that it would be at a distinct disadvantage compared to a simple automatic aiming mechanism using "dumb" bullets.

Furthermore, the comparison with aircraft does not hold up - aircraft are flying at speeds comparable to the rounds being fired at them, where people are typically only able to run at about 1% of the speed of a typical pistol round under ideal conditions. (Going back to The Matrix, Mythbusters examined whether it is humanly possible to dodge a bullet. Short answer is a resounding NO - by the time the round is fired from far enough away that human reaction time lets you respond, it is beyond the range at which you can even see the flash to know it has been fired.)

Missiles and smart bullets definitely have a place on the battlefield, especially at long ranges where atmospheric effects make it possible to miss no matter how accurately a weapon is aimed. However, at short ranges - which include the vast majority of gunfights - dumb bullets are cheaper and perfectly effective, so there is no reason for firearms firing "dumb" bullets to be replaced, only supplemented.

EDIT: It has been pointed out that I have not addressed the zero-G / low-G issue specifically. One of the factors that massively reduces the range of combat - civilian or military - is the size of vehicles and rooms. While there may be very large spaceships and space stations, depressurisation will be an ever-present risk. This means that it is very unlikely there will be huge O'Neill cylinders with massive fields and lakes - the far more likely scenario for a huge O'Neill cylinder is lots of small compartments no bigger than they absolutely have to be so that if there is a breach then only the air / water / people / supplies in one small section are lost. In other words, all personal combat including military actions will be at much shorter range than occurs on Earth. So forget the issue of having to aim off due to Coriolis forces because in a small room it won't matter.

Now let's talk about recoil in zero-G. Yes, it's an issue and yes, it needs to be considered. However, let's look at the scenarios in which someone may be firing:

1. In a static (possibly temporary) firing position while attached to a surface (using a handhold, magnets, suction caps in atmosphere, whatever)
2. Floating away from cover using a thruster pack of some kind
3. In free fall not attached to a surface and without a thruster pack.

For 1, make sure that the hold is sufficient to manage the recoil - any ship or station in zero-G will be designed to allow people to secure themselves for activities with either ferrous strips or handholds / boot clips or (for pressurised environments) simple smooth surfaces for suction caps. As the first principle of marksmanship says "The position and hold must be firm enough to support the weapon".

For 2, the thruster pack should be programmed to compensate for the recoil.

For 3 - well, this is akin to shooting while running or parachuting on Earth. Really well-trained people can do it with some level of success, but it's really bad practice for the same reasons as it is down here - you should get into cover before firing.

Finally, let's expand on the options to assist with aiming. Especially if collateral damage is unacceptable, the firearm may not even be hand-held, it may be attached in a "parrot gun" mount on the shoulder or similar, with aiming occurring by looking at the target and the gun automatically pointing in the direction that will allow for motion, atmospheric resistance etc (even Coriolis force for those rare, long-range shots). Hand-held weapons will have scopes or smart goggles that will do the same job, showing where the round is going to impact after accounting for all factors. Lock-out options will be available so that the gun will not fire unless the bullet will hit an acceptable target at the instant of firing (however that is defined - same problem as for a missile).

Answer 2

Let's build on my comment

As I said in my comment, one of my favorite books is Philip Frances Nowlan's Armageddon 2419 A.D. It's the book that started the entire Buck Rogers franchise — and one of the interesting things about the story is the use of rocket guns.

That novel was written in 1928. The idea has been used in SciFi for (at least) nearly a century — and yet your question is being dismissed as implausible to impossible.

That's boring

Buck Roger's rocket gun was specifically useful because (remember, 1928) they had jet packs. Oh yeah! Jet packs! The epitome of science fiction! And when you're hovering in the air the recoil from a rifle is bad juju.

Recoil has been a problem with firearms since day one. It limits how much ordinance can be brought to bear. It affects how quickly the next round can be fired. It affects accuracy. The history of firearms is also the history of the quest for recoiless arms. And not for space, but for use right here on terra firma.

Consequently, rockets have been and continue to be used in real life to deliver ordinance that would normally cause so much recoil that the operator would be seriously harmed.

Which means your idea has a basis in plausibility: recoil.

Next: are bullets cheap? You betcha! But let's examine that idea. Right now on the shelf at WalMart (well, maybe, ammo shortage and all...) a rifle round is \$1–\$2 per round. I have no idea what the military pays for ammunition — but they use a whomping lot of it — so let's assume about 30% of civilian cost. Let's call it \$0.50/round. And @JamesQF in a comment states that in real combat, 50,000–300,000 rounds are expended per soldier killed. Average: 175,000 rounds (sounds a bit high James, but I'm willing to believe. Do you have a source?). That's $87,500 USD per soldier killed! (James? You sure about those stats?)

What that analysis tells me is that if a soldier can be killed in one shot by a personal smart missile, and that missile cost $42,000 USD, the government would jump at the chance to implement the technology.

Which means your idea has a basis in plausibility: economics and efficiency

Now, we are in combat, whether it's here on Earth or up in space. @KerrAvon2055's answer tells us that the average combat range for the police is three yards. I'd like a source for that statistic, too, because police in the U.S. are trained to the "21-foot rule," (which is being disputed after all these years, but work with me), which basically says that the bad guy must be 21 or more feet away or they can rush you before you can unholster your gun and shoot them. 21 feet is better known as 7 yards, which is why I'm having trouble with the FBI reporting that the average engagement distance is only 3. I'm happy to accept being wrong about this, but it would mean a lot of bad guys are being dragged out of cars or something to bring that well-trained number down.

Now, to be fair, 7 yards isn't exactly a lot, either. But it brings up a point. Could the police use this kind of technology? Absolutely! Suddenly they have the ability to fire a shot at a running suspect and have a hope on Earth of actually hitting them. Better still, the payload could be an anesthetizing gas rather than a high explosive or a simple tranquilizing dart. Personal smart missiles could believably revolutionize police (and military, and space) combat.

Which means your idea has a basis in plausibility: combat conditions

And one more thing, the idea of a target-and-shoot (or, better yet, a point-and-shoot) personal smart missile has one really big appeal: minimal to no collateral damage. Buildings and innocent bystanders don't get shot up in the firefight. Personal missiles would be desirable simply because it allows a nervous police/military to worry less about the mess they might cause if they pull a trigger (not that the military usually cares about the mess it causes... but the politicians greedily looking at that city or space station and linking how valuable it would be if it weren't all shot up might).

But is the technology believable? I mean, pencil-sized missiles?

Folks, this is WorldBuilding.SE. If we can't imagine the ability to miniaturize a technology (something that's already been done for this technology anyway...), then who can? I'm a big believer in the idea that unless the OP says otherwise, the fact that we can't do it today has no bearing on the believability of the idea in the future. But, what would you need to make it work?

• You could rely on thermal tracking. This would work in space. It would technically work on the ground, but @GrumpyYoungMan brings up a point: you need to move around things like trees and bushes on the ground. Could that be done? Sure! We do that already with surface-to-surface missiles. The problem really isn't the trees, it's getting the missile over the top of them in a meaningful way.

• In an urban setting there is the problem of buildings and narrow streets. However, with every passing day, Google Maps becomes more accurate. It's easy for me to believe that the efforts of cartographers and database engineers will result in accurate enough 3D maps of, frankly, all surface locations such that the missile would need little more than to know its starting point and a means of tracking its target and it would know where to go. (Watch that little bounder use a subway tunnel to cut off a fleeing assailant.... It's scare the crap out of the public, but it'd make for a cool story.)

• But could a small missile maneuver in the big city? Once again, why not? A small missile would have an easier time (assuming all the aerodynamic math checks out) than a large missile. Add satellite tracking (or cellular tracking, if you want to extend a terrestrially-based technology) and we have a winner.

Now, to be honest, there would be limitations — but none that I can think of that would cause bullets to be the preference.

1. You have limited range, so the purpose of the personal (e.g., something shot out of a pistol) missile is interpersonal combat. Taking on an airplane would still require something bigger to hold all the fuel and the propulsion system necessary for the speeds and distance involved.

2. You also have limited payload. The physics of "boom" don't appear to compress exceedingly well. On the other hand, Asimov's Foundation series imagined nuclear reactors on a necklace, so I suppose one could imagine a nuclear bomb on a personal missile. And you might need one if you're up against powered armor on a space station.

TL;DR

My conclusion? I think it's reasonable to assume that a story or world that supplanted bullets and other slug throwers with missiles of all shapes and sizes is completely believable. In fact, since it's already been done, I'm having trouble understanding why anyone would suggest that it's not a fine technology for your world.