From what little time Ive spent on this forum, I have searched through it and noticed there have been a few topics posted on "how can I build my own double rifle", or other somewhat related posts. This is not one of those "how to" posts, but rather a link to an interesting forum where a man talks a little about "building his own double rifle". Here is the link

http://www.practicalmachinist.com/ubb/ultimatebb.php/topic/16/936.html

Thought it might interest some of you

CMWill