I personally consider hunting hippopotamus on land (esp. in the sugarcane fields at night) to be the second most exciting form of dangerous game hunting that all of Africa has to offer (first being hunting truly wild lion). A hippopotamus is most dangerous when you’re standing between him and the water.
I have shot 10 of them over the years (till now). Mostly with a .375 Holland & Holland Magnum, except one with a .404 Jeffery and one with a .600 Nitro Express.
Bullets which I have used for hunting hippopotamus (till now), were:
-RWS 300Gr round nosed steel jacketed FMJ solid factory loads
- Remington 300Gr round nosed steel jacketed FMJ factory loads (which employed Hornady bullets)
-Norma 300Gr monolithic solid factory loads
-Cutting Edge Bullets 300Gr monolithic Safari Solid (custom load)
-Barnes 300Gr TSX factory loads
- RWS 400Gr round nosed steel jacketed FMJ solid factory loads
- Labor Fur Ballistik 900Gr flat nosed tombac jacketed FMJ factory loads
I will answer the “Solids vs Expanding Bullets For Hippopotamus“ question which many gents here always end up asking:
For hippopotamus shot in the water, an expanding bullet is better. You only get the brain shot. The skin over the top of the head is relatively thin & so is the skull. An expanding bullet works best because not a lot of penetration is required and shock is far more important.
For hippopotamus shot on land, you’re essentially looking at both a brain shot or a body shot. The hippopotamus body skin is very thick (more than 2“) and a good deal of penetration is required in order to reach the internal vital organs. So solid bullets here really come on their own.
Back when I first started going on hunting safaris in Africa in 1974, the universal rule was to always use nothing but the most strongly constructed solids for hunting hippopotamus. And indeed, I have successfully shot most of my hippopotamuses over the years with solid bullets. The only cartridges which ever gave me a difficult time, were the RWS 400Gr round nosed steel jacketed FMJ solids for the .404 Jeffery. They used extremely thin jackets, which were also quite brittle. Penetration, thus was severely impacted.
On my two most recent African safaris (including last year), I shot two extremely large bull hippopotamus on land with 300Gr Barnes TSX all copper monolithic hollow points. The results were most startlingly satisfactory and It was the first time in my life that I had ever used an expanding bullet on this type of game. I think that for future hunts, a magazine full of Barnes TSX cartridges is the right answer. For hunting hippopotamus on land, they are the only expanding bullets which I can safely recommend.
Is the .375 Holland & Holland Magnum an adequate caliber for hunting hippopotamus in the water ? Definitely. Is the .375 Holland & Holland Magnum an adequate caliber for hunting hippopotamus on land ? The answer is a little more complicated.
When using solid bullets in the .375 Holland & Holland Magnum to hunt hippopotamus on land, I have observed (over the years) that the animals frequently manage to make it into the water before succumbing to the gunshot wound. Solids fired from a larger caliber (such as a .600 Nitro Express) tend to drop the hippopotamus much quicker, when body shots are taken. But when premium grade expanding bullets (such as the 300Gr Barnes TSX) are fired out of the .375 Holland & Holland Magnum on hippopotamus, then even a reasonably placed body shot proves to be fatal very quickly. For this reason, I strongly believe that your .416 Rigby (loaded with 400Gr Barnes TSX) would make for an excellent hippopotamus rifle.
I hope that this helps.
I unfortunately have no experience with hunting rhinoceros, since it's the only member of the African Big Five which I'm yet to hunt even a single specimen of (till now). Hopefully, that's going to change real soon. But the general consensus is that any caliber above .400 bore (loaded with heavy-for-weight solids) is the correct medicine for them.