Magnetic Weapons



""Velocitas Eradico" - "I am speed, and I destroy.""

- Motto of the United States naval railgun development program

Call it a railgun, a magnetic accelerator, a mass driver, a MAC, a Gauss cannon, whatever, they all refer to the same thing: a weapon that uses pressure of magnetic fields instead of an explosive chemical reaction to propel a projectile. This is a fairly common weapon in science fiction. In Real Life they are still impractical for military use, but exist as experimental devices and toys. (but see this!)

Note that there are 2 main types of magnetic weapons:
 * Railgun—projectile connects an even number of conductive rails with a strong electric current flowing through them and through the projectile, which is accelerated along the rails as the circuit tries to expand; essentially a linear electric motor. Not to be confused with rail mounted artillery.
 * Coilgun—uses a series of electromagnets (coils) switched on and off to accelerate a projectile. This device is what "mass driver" meant originally.

Railguns have the advantage that they are relatively simple devices and yet are still capable of very impressive muzzle velocities, limited only by the amount of available electric current and the robustness of the gun. Their primary limitation after the amount of available power is the direct contact between the rails and projectile moving at great speed under current; the stress on the rails is immense, leading to extreme wear and tear. Heat adding up from friction and imperfect electric contact leaves vapors and plasma trailing after the projectile. Earlier railgun designs (proofs of concept rather than anything practical) often needed to completely replace the rails after each shot. Also, the whole circuit from the capacitor forward is under full current and thus pressure.

Coilguns on the other hand involve far less stress on their components, and therefore don't wear out near as quickly. Instead, they are limited by needing far more complex control systems to activate and deactivate the coils in time, and the speed at which the coils can be turned on and off is limited by the coils' inherent inductance (with exotic proposals such as superconducting coils that are laser quenched to turn them off) and magnetic saturation point of the projectile. They are however better suited for launching more massive projectiles at low speeds. The original idea of "mass driver" was to hurl tons of ore from Moon surface for orbital or suborbital pick up.

See also Kinetic Weapons Are Just Better. When it's the main weapon on a ship and it's pointed forward, it's a Fixed Forward-Facing Weapon. It is in no way related to the trope of Sticks to the Back or Magnet Hands.

If you were looking for the anime with the name "railgun", please see A Certain Scientific Railgun.

Anime and Manga

 * These pop up occasionally in the various Gundam series. Older series (Universal Century) treated railguns as unique prototypes or curiosities. They were more ubiquitous in the newer series (Cosmic Era) but were pretty much a "filler" weapon added if a unit had extra space left. The newest series (Anno Domini) have these being the most advanced conventional weapons available before Applied Phlebotinum makes energy weapons commonplace and even then the vast majority of military mecha (being of older make) still use them.
 * Also, the launching mechanism for Humongous Mecha in Gundam Seed used these: The mecha was given an initial boost of speed via an aircraft carrier-style sled and then propelled forwards by magnetic rails extending from the ship.
 * The Gundam Wing spinoff manga G-Unit/Last Outpost introduces an Energy Weapon version of this; the Gundam Geminass' accelerate rifle has a spiral particle accelerator lining the barrel, which can turbo-charge its output for "Hyper Burst Mode".
 * A railgun was used as a turret against the Amaterasu in Starship Operators, with an onboard ammunition manufacturing plant to create more ammunitions (it's on an asteroid). Also, since the anime lacks Space Based Weapon Has Cutoff Range, it has been shown to fire from extreme range.
 * Also the main gun of the Amaterasu herself would qualify, being some sort of particle accelerator it's basically a coilgun accelerating very small projectiles (molecules sized). In one of the latter battles of the series the main gun is used as a sort of massive shot-gun accelerating a very large number of projectiles, presumably rocks.
 * Misaka Mikoto of A Certain Magical Index is a master manipulator of electricity, well-known for her signature "railgun" attack (with coins as ammunition). Her spinoff is even called A Certain Scientific Railgun.
 * Despite the lack of actual rails for her to use, this is theoretically feasible because she doesn't just emit electricity, she controls electricity. She can create virtual rails out of thin air simply by running electric currents in that direction. The rails aren't important except as a conductor, but when you have free control over electricity you don't need a conductor at all; you just need to "push" the electricity in the right direction and thus generate the appropriate magnetic fields.
 * In Crest of the Stars the Gosroth had four very large "electromagnetic guns" that appeared to launch missiles.
 * The titular starship of Infinite Ryvius comes equipped with two detachable railguns referred to as the "Barge Cannons". They can be used by the ship itself as offensive weapons, or picked up and used by the ship's resident Humongous Mecha, the Vital Guarder as twin rifles.
 * Firearms in Code Geass developed in different ways than in our history. From their earliest iterations, actually, they seem to all be what amounts to a small coilgun; gunpowder as we know it either came later, or not at all. That giant silver pistol that everyone and their dog is seen totting? Look closely; it's got a revolving cylinder around the middle, and the rest of it is just coil bearings inside.
 * If our world had naturally-mined non-cooled superconductors around, we'd probably have dispensed with gunpowder soon after we figured out magnetism too. Though strangely enough given the short range of their cannons and handguns that don't penetrate all the way through the body cavity they may be significantly weaker than chemical fire arms.
 * Or it might be a design feature: a bullet that stops in the target is more damaging than one that passes through it.
 * Black Cat: the aptly-named Railgun, which is actually just Train Heartnet's Hades six-shooter electric-powered. Used once, for Train Heartnet's final showdown with Creed Diskenth.

Film

 * The experimental railgun is used in Transformers: Revenge of the Fallen, and manages to do pretty Massive Damage to Devastator.
 * The hand-carried railguns from Eraser, which brought the concept to popular attention and influenced the games of the time.
 * The Meteor Gun used to destroy the Starfighter staging base in The Last Starfighter is one of the most overlooked, forgotten, yet freaking awesome railguns in sci-fi movie history.

Literature

 * Harry Harrison's The Stainless Steel Rat series had Gauss pistols in The Stainless Steel Rat's Revenge.
 * In another Harrison novel, Starworld, La Résistance develops coilguns as their secret weapon and use them to obliterate the Earth fleet. Prior to that, all space combat was fought with missiles. The ammo for the big guns that ran through the spine of the ships was regular old cannonballs, while the ammo for the smaller, turreted versions was explosive bullets. The main character even plays a crucial role in resolving the bugs with the magnet timing system thanks to his skill as a computer engineer.
 * In Robert Heinlein's The Moon Is a Harsh Mistress, the inhabitants of Luna used their electromagnetic catapult (normally used to send grain to Earth) as a weapon to drop steel-coated rocks on Terran targets.
 * Neal Stephenson's Snow Crash has Reason, an arm-mounted Gatling railgun.
 * Neal Stephenson's The Big U also uses a railgun, used to defeat.
 * The "Tin Men" of Dale Brown's novels can use an anti-tank railgun.
 * In Revelation Space, the Demarchists have the space equivalent of a musket: enormous railguns that fire huge chunks of metallic hydrogen out at high speed using thermonuclear bombs as a boost phase. One shot weapons, but really, do you need another shot after that?
 * Well,
 * Bolo supertanks use magnetic weapons as part of their secondary armament from time to time.
 * In Fyodor Berezin's novel Ash, automated orbital magnetic weapons are used by Earth forces as the first line of defense for the base against their former colony. They come in handy when the latter launch thousands of nuclear missiles. Additionally, there are large variants that fire first type of magnetic weapons.

Live Action TV

 * Railguns are used on Daedelus-class starships and on the first Earth starship, the Promethius, inStargate SG-1 and Stargate Atlantis. They are also mounted at ground bases to serve as anti-fighter weapons.
 * For all the good they do.
 * They were effective as anti-fighter platforms. And they were better than missiles against the hive ships.
 * Mass drivers are classed as "Weapons of Mass Destruction" in Babylon 5 and we see them used to pummel the with asteroids.
 * However, keep in mind that the WMD classification isn't based on how they work, I.E. not because of functioning like the type 2 weapon above, but because the "projectiles" they fire, are asteroids/meteors, and they are used for planetary bombardment.
 * In a somewhat less militaristic context, Joan of Arcadia had an episode where Luke and Grace worked together to assemble a demonstration of the principles behind a railgun for the school's science fair. The results were... interesting to behold.
 * In Firefly, railguns and other futuristic weapons appear, but their use is limited compared to good ol' revolvers and shotguns. In the episode "Ariel", Jayne tries to use a stun rifle to breach a metal door, which it's not really designed to do, so he simply throws it aside, muttering "se-niou high-tech Alliance crap!"

Tabletop RPG

 * Rifts was king of railguns. Common as dirt in that setting, 'Railgun' was pretty much shorthand for 'Megadamage Machinegun'...to the point that none of them are ever depicted as having actual rails, or even coils for that matter (though it could be argued that the almost always round barrels could have thin coils built into their length)...and often had ejection ports...and were insanely rapid-fire.
 * Rifts also introduced wooden railgun ammo for use against vampires. Roll that one around in your head. They try to justify it with iron cores buried in the rounds, but while that might work for coil guns, a rail round has to be conductive edge-to-edge and fit the rails snugly.
 * Phase World, and other space-heavy Megaverse worlds with Artificial Gravity technology, have gravity-based slugthrowers as an alternative to railguns. Magnetism is of course stronger than gravity according to physics, but the gravity guns can use any material as a projectile.
 * Techno-wizards build railguns that use telekinesis magic to throw slugs.
 * Traveller:
 * Traveller Classic had the Gauss Rifle and the VRF Gauss Gun (artillery). An adventure in Supplement 6 76 Patrons had a mass driver being used as a weapon very much like The Moon Is A Harsh Mistress literature example.
 * MegaTraveller introduced the Gauss Pistol.
 * In Warhammer 40,000, the Tau Empire make good use of railguns, be it in the form of "rail rifles" that some of their infantry carry, or as the main gun for their heavy tanks and battlesuits. Enemy vehicles don't stand a chance had better hope for some unfavorable armor penetration rolls.
 * For once in 40K, the physics behind them would actually work and is accurately depicted on the models... Though whether their pulse rifles, coilguns that fire tiny globs of plasma via magnetic acceleration would work scientifically is anyone's guess.
 * Also the Necron's Gauss weaponry... is no such thing.
 * Technically it's not one of those either, necron weapons pull matter towards the gun, they are essentially weaponised vacuum cleaners.
 * Also, in every sourcebook describing the things, the 'Gauss' weapons are stated to be entirely NOT Gauss Guns, but that an early theory as to how they operated involved some Gaussian equations. That was wrong, though; we have no idea how they work. And no armor can really withstand them...
 * In French, they are called 'Fission' weapons instead.
 * The Nihtgane, low-tech partisans from the Gaunt's Ghosts series, use big bows powered by twin magnetic generators. They're ludicrously effective compared to lasguns, for some reason.
 * Helps that the arrows are coated in a immensely lethal poison.
 * BattleTech features coilguns (termed Gauss rifles) sized for both combat vehicles (including BattleMechs) and people. The first 'Mech-sized version introduced into the game is still universally respected for being one of the few weapons in the game that can take a 'Mech's head clean off (killing the pilot) with a single shot from a considerable distance. Later versions include the Hyper Assault Gauss Rifles which is basically a magnetic shotgun, the Anti-Personnel Gauss Rifles (essentially a magnetic machine guns). The Word of Blake later introduced mass drivers for WarShips, which is basically a Gauss Rifle that shoots 30 to 90 ton metal slugs, spinally mounted onto a ship.
 * GURPS places railguns as superior to coilguns in terms of damage but they're otherwise the same. The defining characteristic of both is their armor piercing ability and high rate of fire. They also have variable power, you can overcharge them to punch through thick armor or undercharge them to save energy.
 * Stars Without Number has mag rifle / mag pistol among TL 4 weapons. High damage allows a good chance against large predators, combat robots or elite soldiers, but is overkill for common targets; and they lack of to-hit bonuses of beam weapons and/or burst mode, thus generally suboptimal for non-Warriors. "Spike thrower" (shotgun variant) does have burst mode and has best raw damage of all common non-Heavy weapons (even counting TL 5 ones!), but has range slightly above that of a normal shotgun, so usually you get only one attack at short range (where burst bonus is not eaten by range penalty), and then the target either looks like Swiss cheese or gets close enough to bite your face off. As the author explained, they are deliberately given these niches. And, of course, ship-to-ship kinetic weapons other than torpedo — with good performance, but limited magazines.

Video Games

 * The X-Universe has Mass Drivers, which are basically giant miniguns. They shoot their ammo (metal balls) at such tremendous speeds that they go straight through shields and impact on the hull of the ship. Players quickly learn to hate Pirate ships equipped with these with all their heart.
 * Halo has its MACs (Magnetic Accelerator Cannons), which are the main armament on UNSC ships and orbital defense platforms. Rather more down-to-earth weapons include the M68 gauss cannon mounted to some stationary defenses and some Warthog transports. Later novels set in the haloverse include coilgun sniper rifles capable of reducing targets to a cloud of Ludicrous Gibs.
 * The quoted powers of the MACs and coilgun indicate that some details of physics were skipped over. For example: one super-MAC can fire 3000 tonne projectiles as 150,000 km/s. Their relativistic kinetic energy is therefore equivalent to a 10 teratonne explosion. For comparison, that's equivalent to about 200,000 times the Tsar Bomba, the largest nuclear bomb ever detonated.
 * The brute spiker is a railgun.
 * The Eden faction of Outpost 2 has a railgun as one of its weapons
 * MegaTraveller 2 (based on the Traveller Tabletop RPG) had Gauss weapons.
 * The Global Defense Initiative first brought railguns to the battlefield in Command & Conquer: Tiberian Sun on their Mammoth MkII. By C&C 3, all of their main-line tanks came equipped or could be upgraded to fire railguns, while their Zone Troopers carry infantry-sized versions. The Snipers have a small caliber long range version while the Commando have a rapid fire carbine version, these modified variants are only effective vs infantry (though still powerful enough to punch through Cyborg armor effectively).
 * There's a railgun in Jedi Knight: Dark Forces II.
 * Besides missiles, the primary direct weapons of the Caldari in EVE Online are railguns.
 * Gallente players often use them too, if only because their own Particle Blasters are terrible.
 * The Fallout series features a few Gauss (coil) rifles, and even a Gauss pistol.
 * Fallout Tactics has a Gauss minigun.
 * In Resident Evil 3, Jill has to use a gigantic experimental stationary railgun to kill the final boss.
 * Metal Gear REX of the Metal Gear Solid series uses railguns to fire a nuclear warhead. This has the advantage of subverting most nuclear disarmament treaties and being undetectable by radar due to the fact that no fuel is used to propel the warhead.
 * Metal Gear Solid 2 has Fortune, a terrorist leader, use a massive railgun she stole from Lockheed-Martin.
 * The Rail Gun returns in Metal Gear Solid 4, initially as Crying Wolf's weapon, but later acquired by Snake. A fully charged shot from it will take a Gekko out in one hit.
 * Peace Walker has the railgun as the primary weapon of the AI Weapon Chrysalis, from which it can be salvaged for use on Metal Gear ZEKE. A portable version also appears, but, as it requires a separate player to charge up the power to fire, it's a multiplayer-only weapon.
 * The railgun has become the de facto sniper rifle in the Quake series since the second game.
 * Master of Orion 2 has quite efficient rail guns (called mass drivers) and coil guns (called gauss cannons).
 * From the original game, there's the Gauss Autocannon. Each round doesn't do much damage, but it fires 4 times each turn, and unlike the sequel's Gauss cannons, they halve the effectiveness of shields, making them viable for longer than their energy-based contemporaries. 4X, meet More Dakka.
 * In the second game, auto-firing (3x shots) Mass Driver is the best point defence weapon in early and middle game—enveloping Fusion Beam hits 4 missiles (or fighters), but due to bad range dissipation is really good only for the last-moment shot at incoming threat. Conversely, non-dissipating Mass Driver is better against far missiles—ones striking in the next turn or heading to other ships, so you can get 6 shots per weapon instead of 4.
 * Gauss cannons are also an option in the third game.
 * Crysis also features Gauss sniper rifles near the end of the game.
 * UFO Alien Invasion has a railgun with disposable rails packed with each magazine called Bolters, and the in-development version 2.3 features coilguns.
 * The 1997 Freeware Worms-esque realtime deathmatch Liero (version 1.33) has the Gauss Gun, which fires a projectile so fast, it gouges a deep groove in the soil when you fire and is barely affected by gravity.
 * Turn the reload times down to zero and you have a Gauss Autocannon, perfect for chewing up the landscape and jetting around the map as an improvised jetpack.
 * The Warhammer 40,000 FPS Warhammer 40,000: Fire Warrior was the first appearance of the Tau Empire's rail-rifle. They already had the railgun as the most powerful long-range anti-tank gun in the game; this was the introduction of the man-portable version.
 * The Stonehenge weapon in Ace Combat 04: Shattered Skies is a set of eight railguns designed to launch projectiles into space to destroy incoming asteroids. One of them is hit by debris from said asteroid and rendered inoperable, as seen in the mission where you have to destroy it. It's later used as an anti-aircraft weapon with an effective range spanning practically the entire continent it was built on.
 * Chandelier, a weapon of similar design is seen in Ace Combat 6: Fires of Liberation. Like Stonehenge, it was built to shoot down asteroid fragments, however the country that built it didn't complete it in time for when the "big one" struck the planet and the country suffered significant impact damage as opposed to all the other nations with similar operational systems. The fallout from its failure leads to the war that is the focus of the game itself.
 * Joint Assault also features an enemy railgun, used largely as the obligatory altitude-restriction mechanism. You do get to destroy it eventually.
 * According to the canon, Marines use Gauss rifles in StarCraft. This doesn't stop the muzzle flares and "budda budda" sound affect of them firing, though. In the sequel, Reapers use dual Gauss pistols and some snipers go for a ludicrously huge railgun with double laser sights (because one isn't cool enough).
 * The Gauss rifle may actually be a hybrid weapon combining both primer and propellant as well as a coilgun system. This is borne out by the in-game cutscenes, which show the weapon using cartridge ammunition with primers. There's also scenes that show a sharp whining noise after firing the weapon, which also indicate that it probably isn't a conventional firearm either.
 * A campaign-only upgrade for the Bunker essentially installs a second coilgun-type mechanism that speeds up projectiles that pass through it, increasing effective range.
 * Magnetic weapons show up throughout the Escape Velocity series. The Mass Driver weapon in the first game is suggested to be a railgun or coilgun, and in Nova railguns are one of the primary weapons of the Aurorans. The 200 mm railgun is particularly good, having the best range of any primary weapon and a lot of damage.
 * The projectile weapons in Mass Effect are essentially small-scale railguns which use the titular effect to lighten the projectiles they fire.
 * In a hilarious instance of Shown Their Work, the writers slipped in this tidbit to show what the actual ramifications of space-age railguns with mass-reducing technology would be in military training.
 * This is referenced again later, when Shepard is told about a massive crater on a planet that turned out to be from a rogue shot by a ship-to-ship railgun.
 * In Mass Effect 3 on Tuchanka, there's a battery of three ground-to-space railguns of which each is easly 100m long.
 * And later, there's the massive coil gun in the, which is so massive that every shot sends a huge blast of electromagnetic energy through the mainainance corridors next to it. And then you use the barrel as a shortcut to get to the other end of the ship.
 * Even the Reapers use them: those Wave Motion Guns they like to fire? Not lasers. Not particle beams. They are streams of molten metal moving at relativistic speeds. The firing mechanism involves magnetism.
 * Railguns can be mounted on battleships in the Naval Ops series, though they suffer from low rate of fire and narrow firing angles.
 * In Wild ARMs 2, Brad's most powerful ARM attack is a railgun. Because of its destructive capabilities, it can only hold one or two charges at a time.
 * Steel Battalion has two railgun variations. They have limited ammunition (8 or 10 rounds), the non-fixed-mount version is very heavy and will limit weapon loadout options in addition to being limited to a few V Ts, it consumes a lot of battery charge when firing, and there is a delay before it fires...but it will destroy any VT with just 1 or 2 shots, has a very long range, and the projectile travels too fast to slidestep out of the way once fired. The trick to dodging it is to slidestep just BEFORE it fires so that the FSS overcompensates and misses wide, but that won't do the victim any good if he's the target of TWO railguns, one fired a half-second after the other. Needless to say, it's one of the most feared and used weapons in the game's arsenal.
 * The Mechwarrior series has a Gauss Rifles as a standard weapon for the mechs.
 * In Sword of the Stars all the ballistic weapons are of this sort, from the most basic Gauss Cannons that are rapid-fire and relatively short-ranged and weak to the massive anti-planet Siege Drivers.
 * The latter actually fires large metallic asteroids.
 * The Phase Rifle in Conduit 2 is actually a railgun.
 * The Gargoyle's Plasma Lorentz attack in Disgaea 4: A Promise Unforgotten has it generate an electrical current between its arms for use as a makeshift railgun and uses coins as the primary ammunition, not unlike a certain other character. It launches a treasure chest at the end for additional explosive goodness.
 * Every Red Faction game since the first one has had the Rail Driver, a railgun which can pierce through walls and obstacles, has a scope that can see through said obstacles, and in the first and second games, was a one hit kill. The third game features the Gauss Rifle, which could inflict collateral damage, and the Gauss Cannon, an upgraded version only available on certain EDF vehicles and in the DLC.
 * The Forces of Corruption expansion to Star Wars: Empire At War introduces the Vengeance-class frigates for the Zann Consortium based on a new Imperial design that the Empire never got a chance to build (the plans were on the first Death Star when it was destroyed). Their main weapons are four mass driver cannons, which completely ignore Deflector Shields, making them invaluable in fights against Star Destroyers (several of these frigates could quickly take out the SD's shield generator, leaving it vulnerable to the rest of the Consortium fleet, especially if the SD is ambushed with the use of the Vengeance's cloaking device. The downside is the frigate's lack of its own Deflector Shields and the ship's slow speed.
 * In Sins of a Solar Empire, the TEC use twin gauss guns on their orbital defense platforms, the Kol Battleship's signature weapon is the gauss railgun, and the Novalith Cannon superweapon is a giant railgun that shoots giant nukes at planets at near light speed.
 * The Farsight XR-20 from Perfect Dark, which is essentially a One-Hit Kill sniper rifle.
 * In a rare Eastern RPG example, one of the strongest guns you can equip in Shin Megami Tensei I is a railgun.
 * Mass drivers of different size are the most basic weapon in the Homeworld series, ranging from the small and weak pea shooter (weak even for a fighter-sized weapon) to the gigantic and high-powered weapons mounted on cruiser-sized ships.
 * Vega Strike has these as the most efficient (damage/energy ratio) weapons—as kinetics, they also don't weaken with range and partially bypass Deflector Shields. Micro Driver (light gun, 10,5 kg at 4 km/s), Mini Driver (medium gun, 26,8 kg at 3.5 km/s) and Grand Gauss (378 kg at 20 km/s) weapons. The first two and metal balls for them are dirt-cheap and ubiquitous in Human space (and are weapon of choice for Luddites), four of the latter are used as spinal mounted weapons on Aera battleship. There's also a lot of "warhead-assisted kinetics", i.e. cannons hurling shells enhanced with various nasty stuff, up to antimatter cells (Reaper).
 * The New Conglomerate in PlanetSide relies on an magnetic assault rifle, the Gauss Rifle, which fires powerful bullets with an odd firing noise - though it actually fires slower bullets than the more traditional bullet based weapons. The Conglomerate also has a giant rail gun for its BFR, which is almost hitscan and does huge amounts of damage.

Web Comics

 * Peregrine, the Cyborg Space Pirate from Voices has an arm-mounted railgun. He later uses a Mini-Mecha which has an even bigger one, though it's only good for a single shot.
 * Schlock Mercenary has "gauss-gunfoam" pistols that act as coilguns in one of their two modes. It also has railguns as a fairly common armament on warships, although these might use gravy rather than magnetism.
 * In Girl Genius, as an army of war-clanks is being threatened by, the soldiers on board try desperately to kill him before he can attack. This included one of the commanders ordering his crew to "fire the coil gun", which is presumably the clank's main heavy weapon. We never see the result, because that particular clank was scrapmetal in a matter of seconds.
 * The Whiteboard: Roger's paintball railgun.

Western Animation

 * In an episode of Justice League, Vandal Savage uses an orbital rail gun to shoot asteroids down at Earth, giving him "the ultimate high ground" in his latest attempt to Take Over the World. It was attached to the ISS disguised as a contribution from Kaznia.

Real Life

 * The US Navy has tested a 10 MJ railgun.
 * In December 2010 they broke their own record with a 32 MJ shot. The goal is to equip a ship with a 64 MJ railgun by 2020.
 * See the flame that looks like a rocket exhaust? it's actually fire from the friction with air.
 * Navy fired BAE systems prototype railgun in late febuary 2012. Unlike previous models, this railgun is the first model that looks like something that might get mounted on a ship.
 * Homemade coilguns and railguns are fairly popular among hobbyists.
 * Some of the real life nailguns are coilguns, though these are tools and not weapons.
 * Tomayto tomahto.