Gun mechanics in Brink are too poor to begin with, to be nit picky about anything specific. I think what happened was that the developers were too busy concerning themselves with the teamwork aspect of the game and forgot that, at the end of the day, a first person shooter is, well, a first person shooter. No matter how teamplay oriented the game might be, that’s what it eventually boils down to - shooting. It’s just simply unsatisfying in Brink. Aiming down sights doesn’t give you an edge, even though it takes time to do it. Going into a fight, you will be at a severe disadvantage when aiming down sights. Recoil is harder to manage, sensitivity isn’t adjusted properly, cone spread of the bullets is much more apparent, although the spread amount probably doesn’t change, it will feel as if there’s more.
The weapons themselves, for the most part, are interesting and varied but there are problems there as well. For example, the reflex sight blocks too much of the screen. Much more so than any other game I can recall from recent history.
I haven’t actually experienced the problem you’re describing. Are you sure it’s not a mouse problem?