This mod makes the Railroad Rifle shoot Behemoth Boulders. Fun, right?
Warning: Due to my limited knowledge of FO4Edit, This mod replaces the original RR. Activate and Deactivate the mod at your disgression.
Also, modding the weapon in any way will not make it fire the boulders. I will be a bog-standard RR.

Installation is as simple as ever, you put the .esp file into the Data folder of Fallout 4 and enable it in NMM.

Thank you!