H&Hhunter
First, the Zim PH article is more than a year old, actually quite a few years ago as I recall, and it is the one I referenced as pure, unadulterated BS. Even many African PHs agree with that statement. The documentation regarding the particular round in question has been seriously questioned and it is apparently likely that the round was both old and not cared for correctly. There has never been another question about the .416Rem being overpressured.
I've hunted Africa rather extensively - 3-4 weeks per year from 1995 to 2005 alone (missed 2002 when my daughter got married) - in 8 different sub-Saharan countries. I've had one PH use a .416Rigby and many with .416Rem; most who used a bolt gun carried a .458Lott in DG country. Think I have 13 head of DG, 50 species and more than 70 total animals from Africa and I don't do cull hunts.
Once outside RSA, gunshops are like 100 lbs Ele. The most common PG rifle in use by Africans is the .300wm in my experience, and that happens to be my choice since 1974. My DG battery includes a .375H&H, which I no longer use in Africa nor do I recommend, a .416Rem and a .458Lott, which will shoot .458wm in a pinch.
I've had one hunt partner who had to buy some .300wm in RSA before we went into Zambia because his "wildcat" rifle had problems in RSA and he needed to use my .300wm. While I've not had rifle/optics/ammo problems, I have had clients suffer all the above, usually because they didn't listen to good, experienced advice.
Just my observations.