I made my own a little over two years ago, ended with an overall length of 12 inches. It works great with slash cut pipes, it ripped right through the 1st & 2nd baffle it actually sliced the little pipe in half! For the third baffle I had to use an extension. Still usable, I can ship it back as long as I get it back.
Here is a link to my build.
http://s1197.photobucket.com/albums/aa438/Steamroller66/
