Here are weapons with the bug.
In sum up ,these guns are in common that they all use clips reload in a large magazine .IDK what caused this .If you have the same confusion ,please comment or like this post.
BTW ,to test it ,just empty the magazine of the soldier you controlled and press ‘Y’ while holding ‘LMB’ .This will let AI soldier reload the gun.
This bug really have my gaming experience ruined, especially when a radio operator in my squad using a Lee Enfield rifle.Sometimes he will left only less than half ammo to me.If originally 10/20 is enough to do many things ,the 7/8 or sometimes even none he left to me really makes me feel bad😕.