This was still happening to me as of last night, although I am ashamedly using it for my mk48 :D the game would change a shitload if this bug was fixed, would see alot my shotguns and lower grade weapons being used.
will ammunition refreshing to full when logging into the game be fixed at some stage? it will be a massive game changer as the rare guns and ammo whilst ridiculously op will be severely limited in their operation and i dare say we would see alot more shotgun and pistol toting survivors