Not sure if this has already been addressed, but the user feedback when running out of ammo with a semi-auto or automatic rifle or machinegun (I haven't used them all, so can't speak to the behavior of every one) could be tweaked to add more realism.
Currently, you fire your last round and, when you next click the fire button, you hear the hammer fall on the firing pin with a "click." So far, so good--that's how it is.
The issue (and it is a minor one) is, continuing to press the fire button brings the same feedback with every press. The hammer keeps falling, producing repeated clicks. Since there is no round in the chamber to cycle the rifle and cock the hammer, the second and subsequent trigger squeezes should not produce any feedback other than the lack of firing a round. That is, you fire your last round, next you get a click on the empty chamber, then...nothing. You can't even depress the trigger. That's how it works IRL with a semi/full-auto rifle or machinegun.
Currently, continuing the clicks is a repeating cue to the user to reload, which is certainly helpful. However, tweaking it to remove the second and subsequent clicks will add to the realism.
Just a thought. Keeping it as-is certainly wouldn't cause me to complain, but changing it would (IMO) add to the experience. Great game, loving the beta!