Alright so with this model I actually started out with Texturing the Model as I modeled it. Essentially this Gun is a bunch of Cylinders put together so the texturing aspect wasn't that difficult. I started with the barrels got them all designed and copied the first one into a rotation of six barrels.

If you look at the Barrels the back ends are bigger than the front end due to the way you would want to connect the barrels to the mini guns main body. I also created 2 Disks to keep the barrels together and Boolean the holes out of them. One last disk near the bottom of the barrels was created and put in after a little research and also me wanting to add in another for looks.