Mr.Pikachu The Madman

The PipeShot fires pipe bombs at whatever you put in front of it.
To fire the PipeShot, get an auto clicker of your choice, and set it to click 50 times in half a second and then stop.
You then stand on the metal plate, aim with the pipebombs in your hand at the opening of the PipeShot, and press the hotkey you have assigned to activate your auto clicker.
Then step out of the way very quickly after you stop throwing the pipe bombs.
Make sure all of the pipebombs land inside the PipeShot
New Method for firing: If you wish to fire the PipeShot with a tighter spread, a slightly riskier method uses moving directly in front of the barrel and throwing them down the entire length of the barrel. My tests do show that this does yield tighter spread, so if you have a decently close target, you can choose the original shotgun method, or use this newer method that has a tighter spread for long range use.
To install it, replace the info.txt and basic.vox files of the pre-installed basic mod with these ones here.
Make sure to backup the original basic folder just in case something goes wrong or you want to uninstall this mod.