I’m taking 27 300 grain .375 H&H, 10 600 grain .500 A2 and 20 570 grain .500 A2 rounds in two Frankfort Arsenal 211 20 round carriers and three 9 round MTM carriers in a Pelican 1200. When I put on my two locks, I’m right under 5000 grams. Cow buffalo, and possibly giraffe, and zebra culls are on the menu, with maybe some smaller culls if available. It should be considerably more than enough, but I can make do with either rifle should there be equipment difficulties. That saiid, I’d imagine a cull impala at 175 yards will be pretty safe when I’m carrying the .500.
If I remember correctly, the Pelican 1200 is 1684 grams, and my locks are 100 grams each, so there’s wiggle room if I switch to a lighter carrier and locks before I leave.