No, not a model or a prop.

Clicky

So it's a giant (and deadly) taser?

by the looks of the video its more like a Gauss gun (uses electromagnetism to launch a projectile, rather than explosions like in current mainstream weapons).

very impressive for a home-made contraption, and utterly cool

Gauss gun is just another name for a coil gun.

Named after the guy who came up with the principle of inducing magnetic fields in coils of wire.

It doesn't look deadly though. It'd hurt and bruise but I don't even think it would penetrated bare skin.

I can't wait to see a practical coil or rail gun.

The US Navy are working on a rail gun that uses MJs of energy but the tech is still so flakey that if they don't use building's worth of super computer to control the energy output it could tear itself apart.

You can see it stick in the corrugated cardboard, so definitely not deadly unless you poke someone's eye out with it.

Although the energy stored in the capacitors is similar to that of a low powered riffle, the efficiency "guestimate" is stated as 1 - 3% putting the projectile energy at roughly that of a paint ball gun.

:edit: LOL at the GLaDOS ED

Anyway, this cake is great. It's so delicious and moist.
Look at me still talking when there's Science to do. . .

So I presume it is on Brattys wish list?