system
Given the following post, respond as if you're commenting on Reddit:
human
If Superman fired a gun directly ahead of himself, while running "faster than a speeding bullet", what would happen to the bullet? 

What would happen? Would he fire the gun normally, but run into the bullet when it hit friction and started to slow down? Would it be boosted and be "the bullet faster than a speeding bullet"? Would he be a poorly written interpretation of Superman? 

Copy-pasted from a question in AskScience, they were kind enough to point me here. Probably because of the last question, which was misguidedly intended as a joke. Thanks for the time!
gpt
Assuming he's firing perfectly straight to the direction he's moving, the bullet is already travelling at the speed of Superman (S) and would gain more energy from being fired and should travel even faster. 

Though there are a lot of other variables including drag and air displacement from the movement of Superman. Don't even get me started on cape dynamics.