Weird that in loading screen there is "you can unload any weapon by pressing reload key".

No. The entire option was removed completely.
There was an explicit option to unload the weapon - i don't meant re load.
You could literally unload a weapon to gain the ammunition.

But since they removed it for whatever reason, you're only left with your own ammunition.
You run out of it - even there are countless dead soldiers in front of you with rifle which share the same caliber ...

it because ur soldier has full mag so when u reload it would enpty but if u fire one bullet it would reload to full anyway sorry for grammer

and bring back suppressive fire from Faces of War and bring back default off silhoutettes for humans, pls!!

bring it back for AS2

Yeah I don't get it why they took that out :/

Just in case you wonder why we would need it;

... you unload the weapon (the one your enemy drops due to sudden death), get out the ammo and throw it away!