WELL
Ellis Brown has made one and I have shot it and it is FUN
http://bundukipublishing.com/doublerifle.htm

And you can use adapters in side by sides

http://mcace.com/shotguninserts.htm

https://www.youtube.com/watch?v=1-G57tOQ9WU

Last edited by skeettx; 03/26/16 03:56 PM.