How To: Build a Miniature Version of the Navy's Electromagnetic Railgun Weapon

Build a Miniature Version of the Navy's Electromagnetic Railgun Weapon

Simon Phoenix used one in Demolition Man, terrorists got their hands on them in Eraser, and you've probably shot one in Halo, but are electromagnetic projectile weapons more than just science-fiction?

Yes, thanks to the United States Navy.

Today, December 10th, the Office of Naval Research (ONR) officially broke its own record for its stunning, powerful Electromagnetic Railgun, which can hurl a projectile hundreds of miles at super fast speeds— without using explosives. It all went down today at the Naval Surface Warfare Canter in Dahlgren, VA, where they successfully completed a 33-megajoule shot of their railgun device.

Electromagnetic Railgun world record setting event - 2010

A megajoule is a measurement of energy associated with a mass traveling at a certain velocity. In simple terms, a one-ton vehicle moving at 100 mph equals a megajoule of energy.

"Today's Railgun test demonstrates the tactical relevance of this technology, which could one day complement traditional surface ship combat systems," said Rear Adm. Nevin Carr, chief of naval research.

"The 33-megajoule shot means the Navy can fire projectiles at least 110 nautical miles, placing Sailors and Marines at a safe standoff distance and out of harm's way, and the high velocities achievable are tactically relevant for air and missile defense," he added. "This demonstration moves us one day closer to getting this advanced capability to sea."

The Navy's Railgun also improves safety for Sailors and Marines because it will eliminate the need for a high-energy explosive warhead and traditional gun propellants. Removing explosives and chemicals will reduce the munitions logistic chain, plus make it more environmental friendly.

See the full press release here.

The railgun technology uses an electomagnetic current to accelerate a non-explosive bullet at several times the speed of sound. The conductive projectile zips along a set of electrically charged parallel rails and out of the barrel at speeds up to Mach 7.

This all means one thing— super fast penetration. It can hit a target 100 miles away or more within minutes.

The past record set by the ONR was in 2008, with just a mere 10-megajoule shot. The new railgun demonstration showed researchers are steadily progressing toward developing a gun that could hit targets almost 20 times farther than conventional ship combat systems.

(1) Previous record of 10-megajoules in 2008, (2) Previous record of 10-megajoules in 2008

Now, since this awesome weaponry isn't hitting Navy ships anytime soon, and chances are you'll never get your hands on one of these destructive beasts, then I guess you'll just have to build your own.


Granted, you're probably not going to succeed in building an electromagnetic rail gun like that Navy has, but rp181 has designed a smaller version over at Instructables. He shows the steps required to make your own DIY railgun, which he calls a "green method of projectile acceleration, with minimal byproducts and waste."

He also claims that aside from the electricity used to propel the projectile, the materials used do not post a hazard to the environment.

If you have limitless resources (and friends), this railgun project could cost you nothing. If not, you could end up paying a thousand bucks out of your pocket.


Do not attempt this unless you have experience with high voltage and projectiles. This can be FATAL.

To make this railgun, you should already be familiar with them. Some of the obvious steps have been left out to prevent less-knowledgeable folks from injuring themselves.

If you need help or have questions, visit his blog.

Step 1: Parts List

  • Capacitor bank — (18) 400V, 3900uf capacitor's in parallel, which equals 5600 joules. Make sure you stay above 300V, and below 600V. These are harmless to the environment, and are aluminum-based.
  • Aluminum bus bars.
  • (3) 120uf, 300V capacitors.
  • 60A, 600V diodes.
  • 00 AWG cables.
  • Copper bar rails.
  • Aluminum (2" x 5" x 12")
  • Projectiles. Make it close tolerance.
  • Railgun enclosure. Design your own with a 0.5" bore, made from strong material. This one's green.
  • Misc. support equipment.
  • PVC for injector. Use your own design. Look up "spud gun" for ideas.

Step 2: Assemble the Enclosure

For the injector, decide on a good chamber volume. This injection stage was 1-foot long, so 4-feet of 5-inch PVC. The valve consists of a membrane, which is punctured by a nail when pushed in. If you want to go simple, use a ball valve. The enclosure should use many bolts, as to distribute the force. Make sure you material is strong, this is made of Garolite G-11. A cost effecive material is GP03 fiberglass, check out McMaster-Carr.

Your rails should only be after the injection stage. At the front, put "fake rails". This is where the projectile is accelarated by the injector. This should be non-conducting material, like teflon. Before construting the bank, fire the injector, to make sure the projecile can slide through. The projectile CANNOT be too loose, do as close tolerance as you can.

For the REST of RP181's TUTORIAL

Visit the tutorial on Instructables, or visit his website.

(1) Shooting the railgun, (2) Animation overview

References: PopSci, Fox News


Interesting. What kind of muzzle velocity did you get from it?

how long are the rails used in this gun?

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