No Swiftplay-specific changes; identical to the Summoner's Rift version.
Effects
Unique Passive · Fire at Will
Cannon Barrage fires 2 additional clusters of 3 waves over the duration at an increased rate of fire (1 cluster per 1.33 seconds), for a total of 18 waves over the 8 seconds.
Available in
Summoner's Rift · URF · One for All · Swiftplay · Ultimate Spellbook · ARAM · Nexus Blitz