Tested on the Lego map. Right now with the triple harpoon they're all shooting into each other making them bounce off each other and causing backfires/deaths to your own harpoon. While it's REALLY funny, it's annoying.
https://steamcommunity.com/sharedfiles/filedetails/?id=2469182898&searchtext=chrollo
https://steamcommunity.com/sharedfiles/filedetails/?id=3434908250&searchtext=chrollo
It has TTT Hitboxes!