These are really cool looking rifles used by the Shock Troopers in Aeon Flux. They are very recognizable from the movie if you are familiar with it. There are two different ones pictured here: The top (or first) one in each picture is a 'functional' prop, and the bottom (or second) one is a stunt prop. The stunt prop is just a hollow tube and all parts are fixed in place. The 'functional' rifle has a trigger button that when pressed causes the silver 6-barreled tip of the gun to rotate like it's being fired.

The stunt version is lighter becuase it doesn't have any of the mechanisms inside that the 'functioning' prop has. It's made out of almost the same materials though (the exception being the large 6-barreled piece mounted above the handle, this is plastic on the stunt gun versus metal on the other one). This particular gun had the stock of the gun broken off during filming (probably dropped or thrown by a shot Trooper), and has been repaired (seemingly during the production). I also found stage blood under the trigger/hand grip assembly when I took it apart to inspect it.

Inside the functional gun there are several compressed air operated devices which are no longer connected to anything. There are two counter-weights attached to pistons in the barrel of the gun. The only purpose I can think of for these is to make the gun shake/vibrate to simulate the recoil action of being fired (so the actor doesn't have to try to wiggle the gun to simulate this). There's also a piston attached to large barrel on the bottom of the gun to make it go in and out to simulate being fired. The last part of the compressed-air system is a tube that connects to the 6-barreled tip at the upper-most position. Apparently they actually placed projectiles in the 6 barrels that were propelled out by air pressure. There are some scratches on the inside of them that also suggest this (and in the movie you never the Shock Troopers fire more than 4 or 5 rounds on screen in a row). The main difference that can be seen on screen between these two rifles are the little screws all over the functioning one (that are actually holding things in place inside the gun).

This gun originally had power connected to it through the bottom of the trigger handle, but several of them were modified to work on batteries. (If you have one of these, it would be a good idea to open it up and remove the batteries. One of mine started to corrode shortly after I got the gun. Remove the 3 hex screws that attach the stock of the gun to the end of the barrel and pull it off. Of the six screws that appear to be holding it on, only the three closes to the front of the gun are actually holding it there.)

Here they are in use: I'm pretty sure the flames are a special effect.