Well, its a fanciable idea, but there isn't a chance to put it in the game yet.
- IF secondary fire was introduced, then the shotgun would have a double shot.
- You just can't take up the secondary slot for it.
However, I suggested an
idea a while back asking for more weapons, of which you select up to ten to use in the game. I didn't make clear what weapons could be added, so a shotgun that fires slugs would be a nice touch.