Welcome aboard.
Agree with the above information but I would not want to take 100 rounds of ammo between 2 calibers. To me, that seems excessive even if both rifles are used without one being a back-up. Space the rounds out and use foam to fill the space between each caliber and lock it up.
You might need 2-3 rounds of each caliber to check zero. If you hunt plains game and take 10 trophies using 3 rounds of ammo to dispatch each of them then have consumed 36 rounds of ammo between 2 calibers. I am not doubting anyone’s shooting ability only looking at worst case round counts. I do understand the potential to have a scope bumped and may need additional rounds so we bump the total to 40 rounds or 2 boxes of ammo, each caliber. The 5kg/11# of ammo should be of no concern.
Personally, I have not taken more than 2 boxes of each caliber gun I take. I admit I have only been on 2x 8-day safaris and taken 6 trophies on one of the safaris.
All food for thought