In two trips I have never been asked about my ammo, other than the last one where the Qatar agent asked me to weigh it. Never even opened up my ammo box, just took it out of my checked bag and set the ammo box on their scale.
Let see now, I have hunted in 4 African countries and I have watched in a few of the different countries for customs/police to count my ammunition one bullet at a time. It usually starts where they count every bullet individually in each box to make sure they match your rifle. And they did every box of ammunition I had with me.
Also, on departure, I have been asked in all the countries to account for my ammunition and wanting to count every bullet that you depart with. They were not concerned with empty casings.
But again I do not have the experience that you have.
Now hunters traveling with me, did not have the same experience as I was usually the first in line. I had all my paperwork filled out and availabe for inspection and my ammo was accounted for and all my ammunition matched my rifles.
Sometimes this was a teaching moment to the individual inspecting the rifles and shotgun and the ammunition in my ammunition boxes. I explained that the individual boxes contained 20 bullets for rifles and the shotgun ammo had 5 in the small boxes and 25 in the bigger box.. Showed them the marking on the box and proceeded to open the boxes and showed them how to match the bullet to the rifle.
Now the part, that did bother me a couple of times is where you are shown a private room to explain how come you do not have any ammunition to take out of the country, and you think you did good when you were able to leave that room, only to escorted to another room to go over it all again.
Now in the African countries, a person can only have ammunition that match rifles that they have and then can only have a-limited number of rounds availabe (I think that this is 100) and the ammunition needs to be under lock and subject to inspection.