So first to admit, I really dislike the use of laser rifles and the like to replace traditional ballistic small arms, but I still really enjoy the idea of having something that'd be able to not only introduce a significant amount of heat upon a desired target but also, optionally, add something of a kinetic force that isn't plasma. I'm thinking of taking a starwars-esque approach, something like super heated particles, perhaps even ionized but I'd hate to just rip that idea out of the lore. I've considered something akin to a heat ray but I'm not quite looking for something that'd need a concentrated continuous stream to work on something more armored than heavy leather. If it aides in the approach, I'm shooting for something of a 1920+ and fallout combination of aesthetic. Also I do have a sort of "laser" weapon concept sketched up just to aide in giving off the idea I have.
Well, there are two options that I can think of.
1. Microwave/X-Ray Laser.
As the name implies, it's basically a scaled up version of the handheld x-ray machines that dentists use.
- Not as likely to blow up in your face as other energy weapons.
- It's relatively simple (again, compared to other energy weapons), so it's more likely to appear in a post-apocalyptic scenario.
- Pretty much ignores armor; the only things that can defend against it are plate metal (heavy, and the laser will still make it really hot) and Faraday Cages (impractical for wearable armor).
- Provided that you have some unobtainium superconductors and super-capacitors (which are pretty much required anyway if you want energy weapons), the limiting factor on energy output is your power supply.
- Relatively quiet (this is actually a plus from a tactical point of view, but people have come to expect "pew-pew" noises.)
- Like all energy weapons, you'll need good cooling.
- Backscatter. Like it or not, you're probably going to get a higher-than-optimal radiation exposure if you use this.
- As @JohnO pointed out, getting x-rays to lase requires a bit of handwavium. However, this doesn't affect microwave beams, so it's still less problematic than a Star Wars-style plasma caster.
2. Magnetically contained plasma blast.
Your typical "short pulse" plasma caster, as seen on Star Wars, Stargate, and (very occasionally) Star Trek.
- No backscatter.
- The radiative heat from the plasma can leave multiple enemies with burns if they are standing close together (which is typical of mooks.)
- Less time exposed when firing. While Microwave/X-Ray lasers will definitely take an enemy down, you have to hold it (relatively) on target for about a second. With an accelerated plasma weapon it's more like ballistic weapons - pull the trigger and your done.
- Travel time. Unlike lasers, plasma casters don't propagate at the speed of light.
- Remember what I was saying about heat? Well, it is equally effective against allies.
- Extremely fiddly. Unlike lasers, the primary failure mode for a plasma caster is "violently explode in your face".
- Range. Due to thermal blooming (along with several other things), plasma bolts don't go very far even when the unobtainium-based magentic containment is working.
You actually do need a plasma weapon, but "real" plasma devices don't look or work at all like the ones in Science Fiction. There are two main threads of development - devices which create plasma at the target zone, and weapons which accelerate dense plasma "projectiles" at the target.
The first type of weapon uses high energy lasers to generate a plasma on or near the target. When lasers were first developed, it was discovered that the plasma generated by the laser heating the target material would absorb the beam, protecting the material behind it. Over the years, various techniques were developed to overcome this, until it was realized that the plasma itself could be utilised to generate effects.
Various techniques have been developed to manipulate the plasma, including ultrashort, intense applications of laser power to "explode" the plasma, or even modulating the beam to use the plasma as a sort of "speaker" to transmit messages - a sort of remote PSYOPS speaker set. There have been multiple programs to exploit these effects, you can find a survey article here: https://www.popularmechanics.com/military/research/a25091957/plasma-weapon-history/
Generally speaking, these are vehicle mounted devices, that could be carried aboard a large utility vehicle or small truck.
The more traditional device generates a plasma inside the weapon and accelerates it to the target, usually via some sort of plasma railgun. A device developed in the 1990's called MARAUDER (Magnetically accelerated ring to achieve ultrahigh directed energy and radiation) was claimed to create a plasma torid (donut shaped plasma) which on impact would release the equivalent of 5 lb of TNT. To compare, a standard hand grenade generally has 500 grams of high explosive filler. The plasma also released a lot of its energy in the form of X-rays and electromagnetic radiation.
MARAUDER was launching plasma at 3000 Km/sec, and the developed version was expected to launch plasmas at 10,000 km/sec - about 3% of the speed of light. The downside of the MARAUDER was the need for a monster capaciter bank to power the weapon - the same capacitor bank that powers the Shiva Star experimental device. This is the sort of device for defending a fortress or aboard an aircraft carrier sized warship. It isn't very clear how small such a device could be made, but with a bit of handwaving it might be possible to scale down to a 747 sized airplane.
Coaxial Plasma Railgun
Shiva Star capacitor bank
So you can develop the effects desired by using plasma devices, they just are not going to look or work like the ones you see in movies and TV.
- List item
Red hot cannonballs.
Red hot cannonballs have a glorious history!
These time-consuming methods were improved by the French, who used specially-constructed furnaces to heat shot in their artillery batteries at the mouth of the Rhône River in 1794. The United States incorporated hot-shot furnaces into the design of coastal fortifications during the construction of the Second System of seacoast defenses just prior to the War of 1812... The chain of US seacoast forts built between 1817 and the American Civil War, such as Fort Macon, subsequently had one or more hot shot furnaces included as part of their standard defenses.
Your gun shoots red hot cannonballs. Here is the awesome thing: it is a coil gun! You use the coils to heat the iron ball using induction as depicted above. Then you switch the current and use the entire coil assembly to fire the hot ball! More awesome: the gun monitors the magnetism of the iron and fires it just as it starts to become nonmagnetic (as red hot iron is wont). This prevents damaging the gun, you know.
Benefits to red hot cannonballs.
1: They impart kinetic energy. Yes they do.
2: They heat things up that they touch.
3: You can see them flying along especially if it is dark.
4: You can collect and reuse them. Let them cool off a little first!
5: If you stamp messages on your red hot cannonballs they will stay legible. Unless they hit right on the message so best to put the same message on opposite sides of the ball.
Highly advanced plasma pellets.
Plasma weapons in games and movies are weird. You put something at plasma levels of hot out in the open and hope it reaches its target? Even if you managed to, somehow, fire a magnetic field strong enough to keep it together along with it the contact with the air would mean it loses its deadly potential fast. So why not put it in a container instead?
To keep the "bottomless clip" idea the weapons would work as follows:
a container with pressurised gas, probably a liquid under pressure, is kept on the weapon or magazine.
The magazine stores pellets that can be filled with pressurised gas. If you really want to go far, you could claim the pellets are made from an elastic alloy (maybe a Graphenated alloy?) That swells up when filled with the (liquid)gas and forms the bullet shape. The pellets are filled just before they enter the firing chamber.
upon firing, the gas is heated to plasma hot levels. The pellet keeps the plasma together and insulates it during its travel, making sure more of the heat reaches the target. Preferably the pellet is accelerated over time in the barrel through a railgun or similar.
upon reaching the target the pellet will break on impact. Careful machining and managing of the Pellet's structure make it break almost exclusively at the impact point, this means the pressurized plasma will be released in a superheated jet. Basically it would be an alternative miniature HEAT round, which is probably one of the most appropriate names for such a plasma pellet you can imagine. HEAT rounds also use a superheated jet to basically cut through armor.
as an alternative you could use a lower-pressure plasma pellet by simply filling the pellet with less plasma. This activates a delayed-fuse mechanism in the pellet. Due to its bulletshape the pellet would get the opportunity to penetrate some armor first before the delayed impact fuse causes the pellet to rupture, causing a miniature explosion hopefully inside the target. Variations could rupture in specific ways, such as opening the nose of the pellet to create a plasmajet straight forwards, or a bunch of smaller holes could open up that would (attempt to) cut many thin lines in the flesh of the poor victim.
if you want to be really nasty, the used plasma could be a corossive/toxic/acidic/base substance once it starts cooling (or still in plasma state).
You might want to consider a railgun. With a pellet or something up the the size of a pop/soda can for a projectile moving at multiples of MACH, that's going to heat up the projectile (in atmosphere) as well as whatever it hits with a lot of friction.
Even though it would be fired "cold", as it travels through atmosphere it would heat up due to friction. By the time it got downrange a mile or more, it'd likely be very hot. There are mechanisms that happen with air turbulence that can prevent this, but regardless it's going to heat up some.
And a solid chunk of a metal hitting something else solid at MACH 3 or more is going to convert a very significant amount of that velocity into heat. Then again, with a projectile decelerating from MACH 3 in, say, 6 inches, heat is the least of your worries. The shrapnel and debris created from the impact are going to be massive.
If we do some "basic" math with some "basic" numbers, we can get an idea of what I'm talking about.
If we have a 1kg slug accelerated to MACH 3 (1029 m/s), we have over 500k Joules of energy to deal with. For reference, a .357 handgun with a "standard" bore and grain load has 790 Joules of energy, which travels at 440 m/s.
Ok, so that would be on the order of a ship or large vehicle fired weapon, so more than a soldier can easily handle. Let's scale this down a bit. Do we really need to destroy buildings with each shot? Probably not.
A 2 gram projectile at MACH 3 gives 1059 Joules, so a bit more than the .357, but is 1/4 the weight of the bullet. I'd guess that it'd be armor piercing to a pretty decent thickness, due to the tiny surface area of the projectile.
That might be too small, so let's resize it again. How about 2 ounces (56.7 grams)? That's still pretty small, but increases the power to 30k Joules. This might be the right size for a Crew Served Weapon. A mortar round can be as much as 4.14 kg or more, so the railgun rounds are significantly smaller. I can't figure out how much energy a mortar detonates with, so I don't know how that would compare. However, it would likely be enough to disable most vehicles on direct impact and would be easier to aim than a mortar.
SPECIALIZED AMMO FOR SHOTGUNS AND GYROJETS:
Shotguns, paintball-style guns, and gyrojet guns allow a wide variety of sizes and options for your specialty ammo.The variety of shotguns and large-barreled weapons like them are very diverse in appearance, with everything from the blunderbuss to advanced auto-shot and revolver weapons. With a clip system, you should be able to rapidly switch between ammo types for devastating results. So your guns can look super-primitive OR look like Buck Rogers swapped his pitiful beam weapon for something with real technology to it. They can be single shot to full auto.
Okay, it's not a beam weapon, but if the gun is firing a high-explosive projectile, or a really big fragmentation projectile, or even something like a paintball round filled with napalm or thermite, your battle field starts to really light up.
Poison gas can be fired in a pellet, and nerve agents are often contact agents, as are many of the nastier blistering agents like phosgene oxime.
Shotguns can fire pellets to scatter lots of projectiles, slugs to deliver heavy kinetic blows, and they even make rifled slugs to improve range and accuracy(deer hunters can often only use shotguns to hunt, but WANT high powered rifles, so the ammo is evolving to follow). Big, large-barreled guns could even load sabot depleted-uranium flechettes to deal with armored enemies, or tiny shaped charges like mini RPG projectiles can fill the same niche.
Shotgun projectiles lend themselves well to all sorts of less-lethal options like sandbags, compressed plastic rings, smoke, toxins, tear gas, etc.
At longer ranges, almost everything that can be done with shotgun shells could probably be managed with a gyrojet gun. Even the barrels of shotguns and gyrojets are similar. These are basically miniature missile launchers, and weren't developed very far because they had few advantages over conventional guns in terms of just shooting someone. But coupled to a host of specialized ammo types, and suddenly this gun becomes a super-advanced blaster, blowing up doors and firing seeker missiles that can change directions with fins mid-flight. You can have monstrous handguns if desired, firing the same projectiles as the long arms (since gyrojets have almost no recoil and velocity develops after the projectile leaves the barrel). These things LOOK like ray guns, and can bring the same intimidation factor to the field.
Scale these up, and you basically have RPG's and grenade launchers.
What about a grenade launcher, which has some kinetic force, but also releases a large chemical explosion that provides secondary kinetic energy to shrapnel upon impact?