Coil/Gauss Gun vs. Rail Gun

[ZodiacMaster101]

I was looking at rail guns on Google after just looking at the gauss/coil gun that can be found on the gauss hog in the Halo video game series, and from what I can tell they look like they're essentially the same things, and so I was wondering what the difference between the two guns are, could someone please tell me?

 

[Zantos]

Coil guns fire through electromagnetic solenoids (I think the EM part is pretty redundant) by dragging them towards the centre and turning off the magnet so it keeps going. Think of in high school when your physics teacher let go of a paperclip next to an electromagnet and it went hurtling into the magnet.

Rail guns take a mechanically launched projectile and literally accelerate it up a pair of charged rails via either the left of right hand rule.

Coil guns are easy to get hold of the materials but hard to make work. Railguns are a simple design but require a lot of energy and currently unavailable materials.

 

[Daverson]

IIRC, gauss guns are less efficient than rail guns, but it's easier to build a smaller gauss gun.

I think there might also be a upper limit for gauss gun muzzle velocity, but don't quote me on that.

 

[TheMagicIndian]

Since the question has been answered, I immediately thought of this when I saw this thread.

Turn down your speakers.
http://thebest404pageever.com/swf/railgun_fireing.swf

 

[SckizoBoy]

IIRC, gauss guns are less efficient than rail guns, but it's easier to build a smaller gauss gun.

I think there might also be a upper limit for gauss gun muzzle velocity, but don't quote me on that.

Nope, you're right on that, gauss guns are limited in MV by the resistance of the coils, plus, there's more of an energy transfer loss issue (electrical to magnetic to kinetic). Railguns are almost 100% efficient in this respect.

Considering the lack of propellant, that's a lot of plasma:

 

[fierydemise]

To expand on the previous (correct) answers.

When you run current through a coil of wire it creates a magnatic field pulling objects toward the center of the coil. The quick way to build one is to use a capacitor (or bank of capacitors) to put a large amount of current through the coil and shut it off, this way the object is pulled toward the center and then the magnetic field stops after this initial acceleration. You can get more complicated with multistage guns that use a series of coils with careful timing but with a decent coil and capacitor you can make something reasonably effective very quickly.