If you do a pre-clearance on your rifles chances of having the ammo checked is just shy of zip. They just go with making sure the serial numbers match.

I have never seen anyone of those people at the SAPS office check 60 rounds to make sure all the head stamps correspond. Make sure theones on the corners and the sides are the real deal.

Some airlines only allow ammo in a locked case. Confirm with who you will be flying with what they want, and you will have a connecting flight also.