This is all true in the theoretical absolute, but...
1) having been through the first "premium ammo" revolution, when Federal introduced the Nosler Partition in their Premium line in 1977 and instantly outclassed the Remington Core-Lockt, Winchester Power Point, and other Federal Power Shock, etc. ammo;
2) then having been through the second "premium ammo" revolution when Barnes and Swift introduced factory loads for their TSX and AFrame bullets in 2010 and 2016 respectively;
...I remain absolutely amazed at the incredible leap forward accomplished, and I cannot help but notice that bullet failure in the 1970's meant the escape of a wounded animal, while bullet "failure" today generally means discerting philosophically whether a solid deviated a few degrees in its penetration or not, whether a TSX that punched through an animal expanded enough or not, etc. while happily forgetting to consider that the animal was killed, generally very cleanly, which somehow demonstrates that the bullet did its job...
I personally gravitated toward TSX and TTSX because I live in Northern Arizona in the Condor recovery area where hunting with, or even shooting lead core bullets is frowned upon. Had I not, I suspect that the bonded partition also known as the Swift AFrame would likely have been my next step after 30 happy years with the Nosler Partition Federal Premium ammo, which was venerated then and is disdained now for loosing its front core, never mind that this is how the bullet is designed to function, and never mind that recovered Partitions missing their front core (horror!) all come from animals that were killed very dead, and often pole-axed in the process of the front core expanding explosively. Not bad for a "failed" bullet...
Whichever mono TSX or bonded AFrame is selected is relatively irrelevant because I believe that both are equally good, although embodying different technologies, but I have considerably more experience with TSX (.470 NE, .458 Lott, .375 H&H, wife's 9.3x62) and TTSX (.257 Wby, .300 Wby, wife's .270 Win), so I will talk about what I know: the TSX / TTSX. I am no professional bullet maker, nor am I a professional hunter, nor am I expert in ballistics, autopsy, or whatever, but I collected probably over 100 animals so far with TSX / TTSX and,
-- I have never recovered a TTSX from .257 Wby or .300 Wby in shots from 50 to 500+ yards. Did they expand enough or too much? I do not know. but they sure killed "dead right there" everything they went through, from Klipspringer to Sable. My wife's .270 Win make the TTSX fly slower than my Wby, but same experience there.
Note: Maybe this is because we prefer the behind-the-shoulder-double lung & heart shot... Maybe those who shoot for the shoulder recover more bullets, but I never could understand why one should prefer to break a shoulder (non lethal) rather than collapse two lungs and destroy the heart (lethal). Many wounded animals walk the bush with broken shoulders, none with destroyed lungs and heart... "Anchor it!" maybe have been the call of the days of unreliable bullets, but it is definitely outdated with reliable bullets that DO reach the vitals.
-- I think that I have only recovered one TSX: a 500 gr .458 launched by a Lott, that went lengthwise through an Elephant and rested against the skin. Those launched by the .375 H&H zip right through Buffalo sideways (behind the shoulder), and even do those from the 9.3x62. Do the 286 gr .366 expand enough at 9.3x62 speed? I do not know, but the Buffs sure die in a big hurry. Do the 300 gr .375 penetrate straight, with all their petals, or not, in an up-the-butt follow up shot? I do not know, but the Buffs sure die in a big hurry.
I am not making a point about Barnes specifically -- I only selected the TSX and TTSX because I do not reload and Barnes and Weatherby offer loaded ammo with them -- and I am sure that North Fork, Cutting Edge, Peregrine, etc. do just as well.
The bottom line is that it seems that most discussions nowadays about the relative merits and performance of premium slugs, be they monometal or bonded, be tehy 50 gr more or less than typical weight; be they truncated or round nose, etc. are almost purely academic debates where what is truly discussed is how much 'above & beyond' performance a bullet delivers beside killing consistently very fast and very dead.
I will happily concede that killing consistently very fast and very dead has me happy enough. To each our own
or if Eland is already in the menu, then you already have all the reasons in the world to bring the .375 H&H (and yes it is a ready backup for BOTH .470 and .300, which does not hurt by the time you have flown half across the world to Africa;
