This is the FIRST lego shotgun that actually fires a self contained shell which releases multiple pieces when fired. It is largely based off my C3 design, because the shells require a large amount of force to seperate, which I can only replicate with my C3's multiple rubber bands. The shells have a range of approximately 25 feet (to be effective), and have a 1 metre horizontal spread, and 2 metre (max) vertical spread. Each shell is one large piece and 5 smaller pieces attached to it, which seperate when fired. It is VERY powerful. Changes to the C3 Crossbow are:

-improved, more realistic stock (the actual shoulder rest on the back of the stock can bend for added comfort)
-a shotgun sight (approximately showing where fragments will go)
-a shotgun firing runway (gradually widens to allow shell to seperate more horizontally)

NOTE THAT IF YOU HAVE NOT ALREADY BUILT THE C3 CROSSBOW, YOU NEED TO GO TO MY OTHER INSTRUCTABLE TO BUILD IT: https://www.instructables.com/id/The_C3_Crossbow/ THIS INSTRUCTABLE REQUIRES YOU TO HAVE ALREADY BUILT THE C3, BECAUSE THESE ARE THE IMPROVEMENTS.

Please visit my website for other lego guns like this: http://sites.google.com/site/bblegobrickworks/

Step 1: Runway Changes

Basically, jbefore starting this step, take off all the flats and thin pieces on top, so that the run way is only a TOTAL of 1 and 1/3 bricks thick in the MIDDLE of the runway. Then, start with pic 1.

Step 2: New Adjustable Stock

A simple stock, with an bending back piece. Pieces need to be taken out of the back of the crossbow first though, before the actual stock is built.

Step 3: The Shotgun Sight

Basically, 2 short tactical rails, and a piece in the middle to make longer shots with.

Step 4: Y1 Shotgun Shell

Basically a large piece with 5 pieces attached underneath, when the rb(s) hits it, they hit the smaller pieces, which seperate and fire out, along with the larger piece. The runway is like that because then the shell can seperate more horizontally, not just vertically.