Personally think you would very first post on this might be your best option..guesing the .375 H&H and .458 Win would be likely the easiest to come up with if necessary..

Also as 9.3 mentioned---"most" camps have an extra rifle hanging around just in case.

I have not yet experienced my ammo not showing up--I put it in its own locked case and then in my bag with my boots, clothes, etc...have had an issue on a time or two with the guns not showing up at the same time..last year in Zim they showed up 2 days after I got there-come to find out they were just sitting in the Jo'burg airport--no one thought of sending them on to their destination..