>>538308702
Don't worry newfriends, most people here are just salty manchildren that hate everything.
No you don't need someone else to reload a backpack weapon, BUT if you have a friend that wants to do it the reload is very much faster.
It's kinda janky, so if you want to do it you should always stay on an even terrain.

Take out your friendship weapon, and the friend with the backpack just needs to press "E" on you to help. It's useful in very specific circumstances, but you can't really rely on that