making gun models without knowing how guns function is a recipe for failure
its like trying to draw a person but only knowing they have 2 legs and fight eachother a lot
even if you're trying to make a gun that's weird and not possessed of typical gun traits knowing how a gun functions in the first place will help you come up with interesting ways for your quasi-gun to operate instead of just putting things that dont make sense on a handle and saying its a cohesive weapon