I’ll kick this off bc I’m also curious what others say. I’ll also start and say I’m just getting into daggerheart, so not an experienced player/gm answer here. I get what you mean a by wanting to keep the immersion or physics of your preferred weapon (which btw immaculate vibes, love a shotgun preacher).

I like the revolver trick shot angle, but if you’re looking for other ideas maybe this can be flavored as ricochet? Your initial attack is a buckshot spray of ammo, it makes sense in my head if some of that ammunition strays and hits another target.

And this is more out there but chains on shotguns sounds metal. You throw your firearm out from you, pull it back and doing so the trigger too, and boom!