<Lurk moar.
>Learn basic physics, engineering, biology, manufacturing and material properties.
>Look up cut away images of firearms or even better, animations of it firing.
>Watch "Way of the Gun" and ignore 99.9% of depictions of firearms in media.
>If its in Call of Duty/Battlefield its probably a shit representation of the weapon itself and how it is manipulated.
>Look up Project Salvo and learn the lessons the US learned after ignoring the Nazi's data on the matter.
>GO FUCKING SHOOTING! ITS THE ONLY WAY TO PUT ALL THE INFORMATION INTO CONTEXT!