The Conclave Crossfire was a craftable Hardmodegun and an upgrade to the Tactical Shotgun. It fired two shotgun blasts; one was fired from the gun itself while the other rained from the sky towards the cursor. Shots raining from the sky would not pass through tiles.
This weapon was a reference to the Conference Call gun from Borderlands 2, and was referred to by that name in the mod's source files. The weapon directly named Conference Call is referred to as "TrueConferenceCall" internally.
This item used to be known as "Apocalyptic Expulsor", and required Hyperius Bullets to fire.