After making the Anti-Zombie-Crossbow, I had another, even simpler idea to hurl dedicated doom at the zealotic zombies attacking your decayed den. Enter the plastic pipe. You could use a metal one, too, for some additional swing if the undead close in, but a plastic one works just fine. The thing I am holding into the camera on the right is what I used, I think it is 3/4" pipe, but as long as your projectiles fit - the bunch of wooden dowels on the left is what I used - you should be fine.
And as alweays when it comes to propelling stuff to ungodly speed, make sure that you never ever hit or even shoot at persons or animals, and keep in mind that there are things out there that do not take kindly to stuff being hurled at them - say, vases or windows. I do not take any responsibility for what happens next.
Step 1: How to Use
Basically, you use the pipe to propell the projectile using tangiential movement of your arm and releasing it at the right time so it flies in the direction desired. Rather than getting into a complex explaination that would not only be too tedious to read through but would also get you killed trying to make sense of it during an apocalypse, I will sy this: try it a few times, and you will find that your brain does most of the math for you. Checking out the video to see it in action would not hurt, either.
There are two methods of shooting, and I call them overhead and underhand - which in both cases kinda describes how you move the pipe.
Step 2: Overhead
In video game terms, with overhand you trade accuracy for strength and speed. All you have to do is put a projectile into the pipe, gold it over your head, whip it forward and watch it fly. It is a little more complicated than that, but that is what it boils down to.
Practice is key, of course, and over time you will figure out how to aim properly - even though this method does not make it as easy as it could be. I recommend using this method when you are still high on arrows and far away from the undead. Consider it blanket fire with the occasional lucky hit on the distance rather than "zombie sniping". At mid range you can get good results with this, though, but at that range it is pretty much on par with the other method, Underhand.
Step 3: Underhand
As the name suggests, here you swing the pipe upward from a low position. The physics are pretty much the same, except for one important factor - gravity. This is why you need to hold the projectile somehow while you swing it. I do this by having it extend over the tupe slightly and hold it with a finger. The key, of course, is to release it at the right moment, but you will figure that out with a little practice.
Underhand compares favorably with Overhead when it comes to accuracy. At least for me, aiming was easier in this methid, and I think in an apocalyptic environment it is best suited for close-range combat, when you can see the rot in the Zombies' eyes, or when it is more important that you hit rather than deliver the most force.
Step 4: Watch the Video!
After all the theory, lean back and realize that there is still electricity that allows you to enjoy moving pictured on a computer screen. And to celebrate that fact, watch this video where I demonstrate both methods of using the pipe, as well as a slightly biased range comparison - biased because I almost hit the neighbours' house with the first overhead shot and held back slightly after that. Oh, and did I mention that this method has way better reload times than the Anti-Zombie-Crossbow?
I hope you enjoyed this Instructable, find it helpful, and are prepared for any apocalypse coming our way! And remember to be Inspired!