When in africa a once of prevention goes a very long way, I've been several times to both Zimbabwe and South africa, I spent a summer and then some preping to be a PH for plains game in 97, eventually deciding i did not have what it takes to deal with the many different personalities on a African safari, finding some clients could not decide if they were having a good hunt until the telling of the tape, not every animal is going to make gold medal. My mentor ran camps in both South Africa and Zimbabwe, I got to deal with and observe both border crossing officials and those at the airports, bulawayo, and Harare, kimberly, cape town, and Johannesburg, never leave anything to chance or assume nothing will go wrong because you have followed all the rules, it really boils down to the one you are dealing with behind the counter plain and simple, you have to hope he or she is having a good day, arguing won't help applying common sense is pointless, and bribbing/tipping may work but it might land you in jail, if it should come to that let your PH handle that he may know someone who knows someone, I've witnessed a client loose his ballistic tip ammo but not his partitions, the ballistic tip was fairly new at the time and we guessed the guard never having seen them thought they were worth something or perhaps thought they may be military and the guy was up to no good, we had a client loose his rifles at customs but not his handgun, a S&W model 29, we had a client with a 416 Taylor with cases made from 416 Remington, they took all his ammo because it didn't match the rifle perfectly, it kinda did and it kinda didn't, this had not been his first safari with that rifle, another day and another guard it may not have mattered, bottom line if you can come up with matching ammo it would be money well spent to avoid any problems, good luck and enjoy.