Thanks for the reply Rule, you have actually answered the question completely. And the answer is black and white. If there is even a small chance that the authorities require the Cartridge headstamp to match whats on the rifle then that's what needs to be done because there is no way that I would risk having my Rifle confiscated and a hunt ruined by taking a risk with some dumb but officious customs worker in Africa. Thanks again gents for the replies.

Matt.