[SolAndLuna]

The Roaring Rose does function the same as a gun in almost every regard - it lets you use gun skills, it increases range based on the Volley talent, so on... with one key exception - for whatever reason, the shells simply do not apply to it under any circumstances.

I tried attacking normally, using it as a sub-weapon, using spear skills, using gun skills, using Reaping Petals... None of them allow shells to apply.