I saw an article on how to make an automatic arrow turret recently but it was quite large and would not be convenient for small areas. I'm not sure if this one shoots as fast but it should work fine.

1. Place a dispenser facing any direction.

2. Place two blocks to the left and to the right of the dispenser, but one blocks distance behind the dispenser.

3. Place redstone wire in a cross-like pattern. 1 each on top of the two blocks you just placed, 1 in the middle of those two blocks, 1 facing the dispenser, and one behind the one in the middle.

4. Place redstone torches on the front and back of both of the two blocks. They should be facing in the direction you want the dispenser to be dispensing. (you should see everything to begin to flash at this point)

5. Place a lever anywhere around the dispenser.

6. Load the dispenser and press the lever to make sure everything is working.

Look at the image provided if you didn't understand any of the steps or ask me for help. I would be more than willing to pm someone to explain it to them or show them on a server.

This is a tutorial to show how to make a smaller version of the automatic turret design Mr_Moot_101 submitted. This is to help people who want to make a turret but don't have a lot of room.