Sir, I will be honest. I am not used to games that try to be realistic actually be THIS precise with the little things. I will try what you say and see what happens. There is no way in hell you paid THIS much attention to detail, I refuse to believe you! I am definitely gonna try this out and hope you're right! Thanks so much, will reply within a few days if it worked or not.
EDIT: By the Semi-Automatic Rifle you have to partially aim downwards. While aiming with right mouse, shooting at an enemy within the circle reticule on the gun itself results in a miss and having to aim slightly downwards a few pixels. Is there maybe a guide somewhere denoting how to properly aim ranged weapons/what to orient yourself by or am I simply misunderstanding something here?
However, the Crossbow now works like a charm since you told me how important it is to properly aim with right mouse button!