All great information, but none of it really answers the original question.
Not meaning that as an insult, but I was also wondering what point it serves to have the weapon at home but to not be allowed to have ammunition for said weapon.
It being part of the “army kit” certainly makes sense, but that only reinforces the validity of the question; if the rifle is part of the kit, surely the ammo is too. And if the ammo is part of the kit but has to stay on base, then it seems nonsensical to have the weapon stored in a different location…for the same stated reason.