The main issue is the bad description. It says volatile mod but none of the seasonal volatile mods work. Only the limited time event mods count

You obtain the first Volatile Weapon Mod, [b]Shattershafts[/b], by completing the [b]Initial Calibration[/b] Quest that is picked up from Ada. The [b]Initial Calibration[/b] Quest itself requires that you complete two Subquests, [b]Prototype Tuning Traits[/b] and [b]Prototype Tuning Bowstring[/b], which must both be picked up from Ada after you have received the first Quest (on the same character as well). The first of these Subquests requires Crucible match completions while the second progresses from defeating Combatants in Portal Activities. Once you have completed the [b]Initial Calibration Quest[/b] and received [b]Shattershafts[/b] you will be able to pick up Quests for the two other Volatile Mods for the event, [b]Tungsten Bowstring[/b] and [b]Jumpshot[/b]. Note that all [b]Shattershafts[/b] and [b]Jumpshot[/b] can only be applied to Primary ammo Bows; Heavy Bows can only equip [b]Tungsten Bowstring[/b]. (΄◉◞౪◟◉｀)