Which is stronger - Whisper or the Hextech Rifle?

I'm talking about Jhin's hand cannon and Caitlyn's rifle. They're both described as very powerful weapons with assets in them (Jhin can combine Whisper with the cane to make an ever deadlier weapon and the Hextech Rifle can load different types of ammunition into it and shoot with seemingly-unbeatable accuracy)

Ionian equipment and dark magics against a powerful hextechological rifle