The visible bullets in no way represent the actual path of the bullet, so this is purely cosmetic. When you fire a musket/rifle, two bullets are generated - the visible one (shown enlarged in the above image), and the "actual" one that uses realistic projectile values and causes the damage. Or so I've been told by the dev team.
I don't think thats right, in native you can adjust your shot by where the arrow or bolt goes, and since firearms are just modified crossbows it shouldn't be any different, also if you change the stats of the gun the bullets path visibly changes too, if i put shoot speed up the bullet flies way quicker, if i put accuracy down they all have a looser grouping when volley fired, so i think it does represent the real bullet.
If that's what you want to believe, then you're welcome to that opinion
I have been told multiple times though (by every one of the developers at some stage or other) that the visible bullets are not the actual projectile. I believe the reason for this lies in discrepancies between what FSE wanted in terms of bullet randomisation and physics, and what was already implemented for Crossbows, leading to the two-projectile compromise that currently (I believe) exists.
Edit: I haven't looked at any of the NW source code recently, but I believe the stats for the item projectiles are used by both of the projectiles generated (to a degree), but the "Real" (invisible?) projectile is run through a different randomisation and/or physics system upon spawn.
