Morning Heym 88,
When a firearm is carried on board it is mentioned on the NOTOC (notification to captain) which is presented to the captain as part of the stack of paperwork before the doors close .
No objections to approach the flightdeckcrew at the gate ,introduce yourself and give them your businesscard, and ask if they have the time to check if your goods are on board.
100% chance that you will have your answer before the door closes and you can sit back and relax and start dreaming of the trip ahead of you.
Reason for me being so sure is that in between hunting trips I fly a 747 for KLM to pay for all those trips.
When I spot sporting guns on the NOTOC I always go and have a chat with the owner to check out their exciting plans on the way down or their
great stories on their way back home.
Have a good safari( or a great one if you fly wiyh KLM)