This isn't my mesh, but, I downloaded it off the internet to animate and screw with the materials. Either I'm a complete noob, the mesh wasn't formatted correctly, or both, but, after changing the material of a few of the gun barrels, strange things happen when I try to render an animation.
Here are a few sample frames and a link to the file. What is going on and how the hell do I fix it? (pay close attention to the minigun cylinders on the left LINK TO BLENDER FILE https://drive.google.com/file/d/0Bxf7lERLL3TlRjV3YkJCSHRKN1U/view?usp=sharing