Learn how to rig a complex rifle in Blender that transforms into a sniper! What’s even cooler is that the whole effect is completely controlled by one bone, so it’ll be super easy to animate. If you can rig this guy, you can rig just about any weapon you can think of. So come learn more about armatures, rotation axes, bone constraints, actions, and more!

http://cgcookie.com/course/rigging-a-transforming-rifle-in-blender-2-8