fortnite damage incosistency? (all weapons)

[OnlineGamer]

anybody knows why i would do less damage than the other person like I would shoot them in the head with a blue semi auto assault rifle and do 30 damage, they would shoot me in the head with the same rifle and leave me with 30 health out of 150?

yesterday for example I had a gold rocket launcher I shoot it at the guy like literally it is 1 foot away and while I am like 5-6 feet away and I am the one that died while he stayed with 40 health....