John, from what I've seen, if you handload the 416 Rem. Mag. properly, there's absolutely no reason whatsoever to have to deal with unreasonable pressures. I use 370 gr. North Fork solid and soft-point loads at just under 2500 fps., and there are no signs of excessive pressures at all, plus I've used those same loads late-season in the Selous (100 + weather) with not so much as the hint of a sticky bolt lift. Even 400 gr. handloads @ 2400 fps. can be put up that are completely trouble-free in hot weather.
Of course, SAMMI-spec pressures on the 416 Rem. Mag. are about the same as those for the 375 H&H, 300 Win. Mag., 300 H&H, all of the Weatherby magnums, 338. Win., 458 Win., 270 Win., 7mm Rem. Mag. (all are commonly-used in Africa), etc..........
Certain batches of Remington factory ammo were indeed way too hot, there's no question about that, but by the same token, during that era (late '90s, '00) Remington was producing certain lots of 375 H&H ammo that were far too hot as well. I had some Remington 375 H&H 300 gr. Swift A-Frame ammo from one lot that gave ejector marks and a sticky bolt lift in 55 degree weather here at home, and that stuff wouldn't have been suitable for any sort of hunting, anywhere.
Quite honestly, I think that certain such batches of factory ammo as well as poor handloading practices have given rise to the excessive-pressures dialogue. Fundamentally, the 416 Rem. Mag. is a pretty straight-up cartridge to work with.
That's been my experience, anyway.............
AD
