Sep 22 2010Magneto's Getting All Hot And Bothered Just Thinking About It: Guy's Homemade Coilgun


Youtube user Jason went and spent two years building himself a homemade coilgun. But I thought you were a machete guy!

It's almost straight out of science-fiction, but this thing actually works. This coilgun is no toy. Using a large electromagnet, made from 10-gauge magnet wire, it delivers more kinetic energy than a .45 handgun, but less than an M16 rifle, according to Jason. If Jason was able to do this in his backyard with off-the-shelf components, you can just imagine what proper defense contractors should be able to do with a few billion dollars.

OMG can you imagine Jason going ballistic (get it? because it's a gun!) in his next movie with this thing? Goodbye hack-and-slash, hello blast-and-flash! You see, In my script Jason exposes himself to the camera after every kill to add a little more humanity to his character. What? Funny you should ask -- no, no I didn't go to film school. But I do own Big Trouble In Little China!

Hit the jump and skip to 2:50 to see the gun destroying everything Jason could find on his bedside table.

diy coilgun does serious damage with electricity and magnets [technabob]

Thanks to sloppy joe, who's far too delicious to not risk staining your shirt.

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Reader Comments

Thats flippin sweet lol

Do Want. for ZOMBIES

almost first

i'll take ten of them

powder is for pu$$ies.


more kinetic energy than a .45? i doubt it, the thing can't even penetrate a tv remote.

still, that thing is total bad ass.

The coilgun is a lie.

If it has more kinetic energy than a .45, why is the bullet being stopped by a piece of cardboard and a shitty wood fence door? I'm genuinely confused.

I'm now going to have that damn ending song stuck in my head all day.

Fake. The shadows are all wrong.


I think the recoil is between a .45 and a m16, not the penetration/force factor. also it lists the spec as 1-3% efficiency. if at 1-3% it can go through sheet metal, imagine what it'd do at 100% and scaled up by people who actually have millions and the best minds behind it.

pretty cool

It has more ke because of the mass of the bullet. Bullet spins, this coil gun doesn't. With a little modification, this thing can a tank! 400 A, BIG A. Dude~~ I might wanna built myself one this weekend, looks fun!

"9. Ollie Williams - September 22, 2010 12:53 PM
If it has more kinetic energy than a .45, why is the bullet being stopped by a piece of cardboard and a shitty wood fence door? I'm genuinely confused.

My guess would be that he just has no idea how much kinetic energy a .45 has.

It doesn't look like the thing would even break the skin, but it's a cool prototype. he put a lot of nice finishing touches on it. At least he actually BUILT something that actually works, instead of making a CGI rendering of something and callilng it a "concept"

Where "Neccessity" Meets Innovation?

Is the innovation how he changes the proper spelling of the word necessity? I'm confused.

@9 It's because of that giant projectile probably being more massive than a lead bullet. It also has to be a ferrous material (probably steel) to react with the coil's magnetic field.

This is cool but not nearly practical as it is. It appeared to take a while to charge which means lots of time in between shots for zombies to chew your face off.

with this, you can shoot anything without that old-school canon technology. Pew pew pew pencils. >:D

'Tis the work of the devil I tells yah!


It's a pretty cool idea turned into reality, however, I'm pretty sure I could achieve more penetration with an air compression rig. Or my penis.


A 45 has more recoil then an M16. The M16 has a 14 inch buffer spring, almost no recoil.

Look ma, no powder burns! That could be one sneaky little focker!

uh yeah, i doubt a .45 bullet fired from a hand gun would bounce off the bottom of a toaster over or a cardboard box.

kinda surprised there aren't more people building them.

Makes me want to play a good FPS


Me too! My favorite one is called Real Life. No respawn tho.

He has slender fingers like a lady-man

"14. Randommolecules - September 22, 2010 1:15 PM

It has more ke because of the mass of the bullet. Bullet spins, this coil gun doesn't. With a little modification, this thing can a tank! "

No, the formula for kinetic entergy is 1/2(mass*velocity squared)

the higher mass will not come close to making up the lower velocity. the kinetic energy of this thing looks more similar to a tossed baseball than any firearm, he's just exaggerating a bit for wow factor.

and agreed, with some modification this thing can a tank (whatever that means). basically, if this was a completely different device, it would be awesome.

Almost as good as my slingshot that I used when I was nine years old.

What kills me (no pun intended) is that these guys will spend big $$$ and devote hours upon hours to build these fake guns when they could just buy a real gun and shoot it.

I know, I don't get it because I'm old and lonely. Err, I didn't mean lonely, I meant I have no friends....Doh! It might have something to do with my arsenal of weapons that I show to perspective hosta....girlfriends.

OK, it's not fake after all. Maybe I should have watched the video and THEN commented. Will I ever learn? No, I think not.

he broke a lot of cool stuff to demonstrate this, he should've used it on the empty skull of a firstard

hmm. at its current state it lacks stopping power, most definitely. If it were played around with by some real defense contractors, and not an amateur backyard dog and pony show, it would definitely be worth some recognition. I'd love to see it even juiced up to 50% and see what damage it does to a slab of pig. Props to the creator, but this technology has prolly been tried and played around with for 50 or more years.

Let's see this in the next Halo game, please. You know, the one that won't be made by Bungie and will probably suck balls after Microsoft botches it up.

Metal Gear?!?

I like the way it displays the mark of the beast when he turns it on... that thing is demonic!!!

You guys sure he just hasn't turned it up to its full potential in the video? I mean, if it really has the power of a .45, I'm pretty sure he wouldn't be firing it around his neighborhood. It seems as though he can control the amount of ke that is produced/released from the coils, and therefore wouldn't risk fucking up neighbor's property, himself or some other shit. Just sayin...

You are all ignoring the fact that the man killed a F-35 Joint Strike Fighter with it.

glados at the end just made it so much better...
i dont think i understood more than 10 words that the guy said...
that is badass

This would make a pretty sweet NERF dart gun!

A company called Metal Storm has already developed this for the military.

is it noted, "delivers more kinetic energy than a .45 handgun, but less than an M16 rifle, according to Jason" that being said, according to Jason! so he crunched some numbers wrong or wasnt showing us its full potential. could it do as much damage as a .45? its very possible.

Seems to actually do about as much damage as a .38 service revolver. BUT I'm not knocking it. that guy did an astonishing and rather alarming thing!

I love it when he turns on the DVM and it shows 666 first, awesome, great job, man.

Metal storm works differently.
It still uses explosive propellants, but they are heat resistant and electrically ignited via coils.

penetration doesnt equal kinetic energy. that is a large round traveling at slower speed, but it could have the same or more KE than a smaller round at higher speed. hitting someone in the gut with a hammer wont go all the way through them, but id guess the KE of the hammer at the point of impact would be close to a gunshot. not to say his figures are accurate, but doesnt mean they arent. only way to know is to know the mass and speed of the projectile.


Wrong. Did you not read 29?

Kinetic Energy = 1/2 x mass x velocity(squared)

Thusly an object of equivalent mass travelling at twice the speed contains four times as much kinetic energy. Velocity is the more important factor in many projectile weapons. Why do you think the military uses the M16? It's a relatively low mass round (.223) with a shitload of powder behind it.

Remember he was shooting a much larger projectile than a .45. The larger projectile would have more mass and therefore have similar kinetic energy at a lower speed

In regards to 29 i've never seen a baseball clear through sheet metal


Depends on the application. The M16 has a high velocity and a relatively small round. This is done for range and cost effectiveness. The M16 has relatively low stopping power, at close range it has almost no stopping power. That is partially compensated for with a 3 round burst setting when needed.

The 45 on the other hand has a very large round and a much lower velocity. It has poor range but large amounts of stopping power. The 45 was instituted by the US government to fight the flips because the 38 rounds being used wouldn't put someone on a suicidal charge to a position down fast enough.

The larger rounds with lower velocity tended to transfer more energy to the target at the cost of ranged effectiveness.

During the Vietnam era the US started reversing this policy because the need for stopping power diminished and the need for cost effective rounds with better range was needed.

That's the reason why we use 9mm and 5.56 rounds today.


I was under the impression that the M16 was used for the purpose of injuring and not killing therefore taking out three soldiers instead of only one aside, you're absolutely right. I wasn't taking into account the surface area in regards to effective transfer of kinetic energy and hydrostatic shock, but simply the straightforward newtonian kinetics formula.

When all's said and done, fuck a small round (sort of). My home defense is a .357 magnum and a .40 XD. Sort of comes into account due to the .40 S&W round. Larger than a 9 and a .357 mag (obviously) but with less powder than say... a .38 special +P or the beastmagnum. However, the .40 S&W was developed for capacity and, obviously, cost effectiveness while still having the ability to inflict hydrostatic shock. Win! At the same time, the smaller .357 magnum has a much higher energy transfer due to its velocity.


If he is able to increase it efficiency, change the design of the projectile and the composition to become more lightweight and to react to magnetic field better will be the ultimate sniper riffle, it will small and compact with the bang.

Guiz, arguing on the internet... well you know the rest...

.45acp top out around 518 ft/lbs according to wiki moving at a speed of about 1,000 fps or about 680 mph for an object about a half ounce (if I can do maths)

this round seems to be much much larger than a .45, though the overall force does seem to be lacking in the video.

As some people have pointed out, the round is much larger than a .45. And that is the problem. It should have been able to shoot through that metal microwave. not just dent it. It probably needs to be redesigned with better ammo other than a giant hunk of metal shooting through plastic objects.

Sweet. It´s also frekin quiet. Like it´s got a built in silencer. No powder.
A sniper´s wet dream.

Oh boy here we go, two science nuts battling over who's hypothesis of velocity is correct. The funny thing is, I bet they can't even explain two-body motion without googling it. LOL!!!

@57 You mean two-body motion, like doggy style?

Of course, if anyone disagreed with your post, milo, you'd just be like "see haha guy googled it."

I'm not a physics major or mad science brain, I've just taken a class or two.

"And the Science gets done.
And you make a neat gun."

@60 for the people who are, still alive.

Oh yeah. Alsooo. Why is this not an EMP gun?
I bet the electromagnet impulses could be harnessed better for taking out cars/phones/electrics within a 10m radius.
Need someone to do that.

I think I'd prefer a BB gun, WTF man that's weak

Shoot a wet phone book. That's a more realistic benchmark.

meh id rather have a beer



It's an F-22, not an F-35 lulz.

I want one of these so I can play with it...

so... I'll just hold a plastic remote control in front of me to protect myself... good plan :D

" 50. CPT Obvious - September 22, 2010 11:08 PM
The M16 has relatively low stopping power, at close range it has almost no stopping power. "

CPT Obvious doesn't know much about ballistics. he seems to be suggesting stopping power increases with range. That's not even getting into the more than double muzzle energy of the .223 vs .45.

If you made it this far down in the comments, congratulations. Your reward is the explanation for the misleading figures.

The capacitors have 1.25kJ (1250 Joules) of stored electrostatic potential energy. This is more energy than the 600-900 Joules of kinetic energy possessed by typical .45 caliber pistol rounds and it is less than the 1500-1800 Joules of kinetic energy of an M16 round. Jason, or someone at Technabob, is pretty ignorant to be comparing the potential energy in the capacitors to the kinetic energy of various bullets.

It's important to note that this coilgun has an efficiency of 1-3%, so its projectile has a kinetic energy of only (0.01*1250J) to (0.03*1250J) or about 12-40 Joules. This is assuming the 1-3% efficiency represents variation he sees over several shots with each shot fired by capacitors charged all the way up to the full 1250J.

Coilguns are really inefficient fundamentally. When the iron projectile is "saturated" the induced magnetic field in it cannot get any larger; this is governed by the physical properties of iron. Once saturated, you don't get nearly as much of an increase in pulling force by applying a larger external field with the coil.

Thus, if his coil is saturating the projectile, charging the capacitors up to a lesser amount may yield higher efficiency. It wouldn't get more energy out, just waste less.

is the barrel rifled?

@69. mcfeely smackup

Nope, stopping power is how much energy can be transfered to the target. So in general, a larger round traveling at an optimal speed will transfer more of it's potential energy then a smaller round propelled at higher speeds. While munitions with higher velocities can be more deadly, larger rounds with more surface area tend to transfer more energy to the target and generate more knock down power. How effective a round is, is determined by bullet weight, circumference, velocity, aerodynamics, target composition and range. It's not a simple calculation of velocity and weight.

I never said stopping power increases with range. I just explained the reason the 45 was developed was for stopping power and the reason the 5.56 was designed was for range, accuracy and cost effectiveness. On a minor note I suggested that heavier rounds have more stopping power, while lighter rounds tend to have less stopping power but was a trade off made by the US military for cost and effectiveness reasons.

An example might be taken from large game hunting. A 300 weatherby is considered a great round for moose and elk, but not so much for brown bear unless you are shooting from range. Why? Because the relatively small round traveling at high speeds tend to blow through almost anything it hits. This is great for elk and moose in wide open fields, they'll die, maybe not right away but you can hit them from very far away and not expect to be in any danger. When it comes to brown bear, most people would use something like a 454, why? Because they are a fairly large round, while not exceptionally great at long distances, can transfer large amounts of force to a bear that is relatively close and set it on the ground or push it back with each hit. A 300 wthby on the other hand would waste the vast majority of its force by blowing out the back side of the bear. Sure the bear might be dead if you hit it with a 300 wthby, he just might not know it until after he's ripped your head off. The 454 on the other-hand would blast craters into the bear with every hit transferring almost all of its force to the bear, ensuring he never makes it to you.

That is the difference and a great example of the advantages of larger and smaller rounds and the amount of powder we put behind them and why it varies so much.

The points I was trying to make are two-fold.

First @13 who said...
"I think the recoil is between a .45 and a m16"

That's not true because the recoil on most 45's is greater then most M16's. I'm not saying that an M16 has less energy, it just has less recoil transfered to the shooter because of a large buffer spring.

Second @29 mcfeeley who said...
"No, the formula for kinetic entergy is 1/2(mass*velocity squared)"

The mathematical formula for what a bullet does and how effective it is, involves a lot more then your simple mathematical formula. You have not taken into account many, many variables. Also a lot of variables that effect a bullets effectiveness are not constants. If all we had to worry about to make an effective projectile weapon was 1/2(mass*velocity squared) then we would only need two or three different calibers of weapons and 2-3 cases.

Unfortunately that's short sighted and not the case. You didn't take into account bullet composition, target composition, aerodynamics, wind speed, bullet spin, bullet spread, gravity and blah, blah and blah.

Effectiveness of a bullet is not simply determined by 1/2(mass*velocity squared), So no, I do know something about ballistics and yes, you obviously don't know much about ballistics. Also the .223 is more commonly known as the 5.56.

Maybe one day you can get it to shoot plasma.

You seem to be assuming that he has some way to actually measure the kinetic energy generated and some way, additionally, to actually figure out what the efficiency is. You can't just clock a bullet with regular speed detection devices. I haven't seen a cop's radar gun display "2972 fps." Chances are the specs are best guess estimates.
Wind speed tends not to effect bullets very much other than their left/right drift (thus half, full, and no value winds - look it up). Bullet composition tends to account for penetration more than it does for energy transfer and loss of transfer due to tissue elasticity. The shape of the bullet helps determine energy transfer. Small cross-section = less transfer. Large cross section = more transfer. And the .223 is the civilian version of the 5.56. The armed forces use different types of rounds with different grain and composition. Even large, blunt rounds like the Revolution era musket balls could penetrate flesh, thin metal, and wood.
The real test of the weapon shown would be to construct one on your own. Then all questions about its effects and whether it is real would be laid to rest.

@76 Your an idiot.



Curiously it doesn't fit the definition of a firearm (at least in NJ - a device that fires a projectile propelled by an explosive force or propellent) does this mean its legal to carry it around with you??

Aw, shoot.

Hellz yeah for "Still Alive" as end credits xP

Would you Adam & Eve it?!? There's a whole site dedicated to this stuff:

Those bolts would fly more efficiently if you had carved a few stabilizing fins on them.

Typical american , spended two years on making this 10 meter range gun which can only pinch rather then penetrate, but overall no doubt kid got brains but if he use it for some other real constructive purpose perhaps he can make something better.

Typical Euro-trash, saying stuff like "spended two years", but overall you have no brains because you let us American's dominate the world over the last 80 years, so all you can do now is cry about us on the internet.

So show some respect to your superiors or we'll invade you next.

with a name like mandeep i would think this person is from south east asia.

this is data on gun :
400V @ 1248J Source ??J kinetic ??m/s and 30 seconds charge. One stage.
Projectile: 40 grams, 9.45 mm dia, 66 mm length. 40W ZVS DC-DC converter. Mass: 3515g

@13 NO ONE can get it upto 100% efficiency. In fact the theoretical maximum efficiency for a coilgun is around 38%.

To increase efficiency beyond that, you need to accelerate the projectile with the columb force instead of a magnetic field. In other words, build a railgun instead of a coilgun.

The large charge time is something, no team of engineers can overcome while still keeping the device portable. The rate the capacitors charge is directly related to the amount of power the batteries can provide. Plug it into a wall, and you can fire it as fast as you can load it.

Well... not entirely true that no team of engineers could improve it... NASA DOES have 3lb nuclear power cells... So a better battery would solve the problem.

As for railguns, if you were to solve the power problems that affect both railguns and coilguns. Rail guns while having far superior KE (the projectiles can reach 5% the speed of light on home built units), has it's own problems which make it unsuitable in the near future as a military hand weapon. The round has a high chance (%3 on professional units, still too high) of getting arc welded to the rails. If that happens the next round that it attempts to fire will either rip the railgun out of your hands, or your arms out of your body, depending on how good of a grip you have.

So yes, there is a reason coilguns and railguns aren't used by the military (except the navy, who have very large railguns mounted to ships). The technology simply isn't ready. But soon, better allows, better portable power supplies, and soon you too can cause wall of rock to explode in an old closed down quarry with a single shot.

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