Hallo Jaco,
Even though I have but a wee drop of water's experience, in your ocean of experience on the subject at hand, IE: shooting African heavy game animals / selecting proper equipment and related subject matter (to include bullets), years ago I totally concluded that there are quite a few premium bullets today that, out-perform old fashioned Hornady and similar lead core/jacketed bullets.
This is multiplied on sometimes difficult to clobber buffaloes and other heavy game, especially for those who insist on bringing high velocity rifles to hunt at close range.
Most USA hunters are suffering from Velocity Madness, as Pondoro Taylor so well phrased it, just after WW II.
I used to have it bad but, my first trip to the Lowveld / Limpopo cured me of it finally.
The other side of that coin is that I do like old fashioned Hornady bullets within their velocity limitations, especially in round nose configuration / heavy for caliber design on many of the species I have used them, here in N. America, especially Alaska where I live.
Such have been my bullet of choice for 3 out of 4 African adventures, with A+ results (zero wounded animals lost) in .375 H&H, .30-06 and .450 No2 Nitro respectively.
But the success is partly because the animals were hit where they are supposed to be hit, or at least 99% of them (I'm only human) but, they all still went down and also, partly because I have never tried to use such old fashioned (1890's technology) bullets beyond the impact velocities they were designed to handle.
Likewise, my meager experience with double rifles has shown that two of the few I have owned, regulated best with the above described Hornady's, not Woodleighs as I had expected.
The buffalo in the photo by my name was taken with a left and a right (as that's how I prefer to run my triggers) with Hndy DGX and DGS respectively,
Both impacts knocked him off his feet and both were fatal, he just was not convinced immediately after the first one pitched him onto his chin, he stayed down after the solid.
I've kept the mushroomed DGX as a conversation piece, the solid is still somewhere along the banks of The Olifants River.
These meager experiences could be easily beginner's luck and I totally get that but the point of my long, painful rant is: A hunter should never drive an old fashioned bullet at higher velocity than it was designed to handle in the first place.
If I ever decide to use a bolt action on heavy game (I have several that were made for that), I will prefer the A-Frame for a soft and a monolithic for a solid (if such will hit to close enough to the same point of aim as the soft).
I believe that you chaps who shoot large animals and guide people to shoot large animals for a living, do know way more than I ever will and if I book with you some day, I will bring whatever bullet / bullets you ask me to bring.
You must keep well,
Velo Dog