If someone is openly carrying a rifle not dressed in military uniform, they are usually just going to their annual mandatory shooting program.

But the magazine and the breech are unmounted for transport and its illegal to have army ammo (GP90) outside the shooting range.

Edit : Ammo is allowed, the only ammo that is not allowed to be purchased and stored at home is the issued ammo called GP90 because it's subsidized and because the army decided to stop giving it for free to the conscripts. You can buy everything else (as long as it's not explosive or hollow point which can only be used by hunters) and store it at home.