Rapid Firecannon states that energized attacks gain 35% range.
If Rapid Firecannon is bought on Graves, and graves auto-attacks a target moving away from him, the energized damage will proc at an extra 35% range but the bullets will not travel the extra distance.
Steps to reproduce:
1. Pick Graves
2. Buy Rapid Fiercannon
3. Energize an attack and auto-attack a target moving away from you.