When a rifle operator changes fire mode he feels the click in his fingers.
In a video game we can hear the click sound, so this click should be louder and this click response should be faster so we can really change fire mode more times during combat.

In present state it doesn't respond very fast and the worse part is that if we change firemode many time very fast it can't keep up with our change speed.

Its a simple detail but it really need some improvements. Other games does that a lot more fast and fluid and this has an important impact on gameplay.