Doublestar showed off their Zombie X Chainsaw Rail Attachment at SHOT Show 2012. It is a fully functioning chainsaw, attaches to a Picatinny rail with the power button on the left hand side. It lets you mount a battery-powered chainsaw on the assault rifle of your choice and cut through zombie flesh like a hot knife through butter. After more you can see a DoubleStar Zombie-X AK-47 which a weapon specially customized to battle zombie hordes by attaching a battery-charged chainsaw to the end of the barrel, as well as a EOTech Zombie Stopper XPS2-Z Holographic Sight which lets you line up your target through a holographic biohazard sign.
As visually awesome as it is, a chainsaw makes a very risky Zombie weapon. Close combat and infected blood flying everywhere. Plus a battery powered electric motor wouldn't hold up against hordes of Undead. Youd be much better off just stickin with the rifle.
