Been a while, but I've posted a couple of time in this thread... Can't really remember the exact words of my postings but no matter, I'm old and set in my ways so the thinking hasn't and likely won't change.
My preferences are formed from experiences. I was always a 270 Win and 30-06 Sprg type hunter until Africa... which really began in about 1985. Age plus experience have both tempered and set my opinions. Not unlike my late friend and thought brother Bruce Moulds- will always miss you Bruce.
Yes, the 338 is a great caliber. But it has limitations like they all do! There is simply not a single caliber or cartridge that will do everything better than all others. The 338 in most of its various forms possibly does a few things better than most all for certain things- but not all things.
My background for opinion is based on field experience and usefulness to my style of hunting. I have shot a large variety and number of plains game in the 200-500 lb range. I know the 270 is adequate for most as is the 30-06. History proves it. however, I once had a miserable failure of a 30 cal bonded bullet traveling at modest vel on a 300 lb plains game animal. That combo should have been right in the middle of the wheelhouse for that caliber, velocity and bullet design for that animal. But SHT happens. I did not lose the animal but it took a full day and 3-4 miles of hard work and superior tracking effort by some talented trackers to recover it. After that, no more- I was permanently converted to the "use enough gun (and bullet)" fraternity.
40 some odd years earlier and on a different continent, my nephew was on a DIY mountain grizzly hunt on the east slope of the AK Range and shot a large boar at 200-250 yards with his 338 WM shooting factory 250 gr Nosler Partitions, IIRC Federal Premium ammo. At the shot the bear did some gymnastics and proceeded to rocket downhill, cross a small creek and start up the other side where my nephew put another shot into it. The second shot was also a hit but the bear barely reacted. It them proceeded to top the next ridge and went out to sight into the alders. That was the last time we saw that bear. The blood was bright red as it should be for a good hit. Not a chance it was bullet failure either, IMO. The impact velocities at 225 and 275 yds in that cartridge/rifle are right in the preferred ideal range for the Partition. Who knows, but I suspect single lung hit, unlucky to not do more damage and a very tough tenacious bear. Just an anecdote, but part of my opinion experience archive.
After the 30-06 mess with the bonded bullet and a stretch of building two custom 35 Whelens- one regular and one improved, I had an epiphany so to speak. Not complicated just common sense to me."Use enough gun and bullet" - no matter the game. So after the 30 caliber bullet failure on the 300 lb antelope (black wildebeest) and the years earlier experience with my nephew, I did some serious inward thinking. I drew my own parameters for caliber, bullet type and design for game falling into gross categories. I sold all my 30 caliber hunting rifles, 8 of them I think, keeping only my first big game rifle, a pre-64 Win 94, 30-30. I also kept my old Win M70 270 strictly as a deer/pronghorn rifle. I built two 338-06s on Win M70 CRF actions. I built a CRF MRC bolt rifle in 450 Watts. I have two Win M70 416 Rem Mags and two 375 HH Mags- one a Win M70 CRF and one a BRNO ZKK.
After shooting, developing loads and testing bullets for both iterations of the 35 Whelen, I asked myself a simple question. "Self, what will this 35 caliber rifle do better than any other"... while thinking of the various game animals I might hunt with it? I couldn't think of any- sold both.
Now, after many, many plains game and dangerous game from springbuck to buffalo with various calibers, I have formed my own opinion for hunting these type big game with my style hunting- hunting close and not shooting farther than the point blank range of the bullet/rifle/cartridge. For the 338-06 and 225 gr bullet that is max of 275-300 yards with steady rest and stationary animal. For the bigger rifles, the max range is quite a bit closer. For plains game like blue wildebeest, IMO the 338-06 with a tough and accurate bullet like the 225 TSX is about the max animal, if I am comfortable in placing the bullet precisely. No matter how cocky I may feel about the bullet and accuracy of the 338-06, inside I know not to use it for eland. That is why I have the 375 and 416 and they do work extremely well for eland and I do not feel overgunned by using them! So there it is for me. Hunt as close as possible, less than 300 yards for certain, with 338-06 and use a tough bullet loaded to about 2500 fps. Use a 300 or 400 grain tough bullet respectively in either the 375 or the 416 for eland. My general thoughts- a 30-06 is not a 338-06. A 35 Whelen is not a 375 HH and neither is a 338-06 and neither is a 338 WM. And a 9.3 x 62 is not a 375 HH either. I really don't know what a 6.5 "ass blaster" or "man bun" is. I even had a 260 Remington custom bolt rifle built to my specs and it was truly a beauty of an accurate rifle, especially with 125 gr bullets. And seemingly deadly for the two deer I killed with it. But did it do anything better than some other beefier calibers like the 270 Win? Nope. Even had a really nice 8mm Rem Mag once. Very deadly on plains game sized animals and IMO maybe one the best elk cartridges out there. But would it do better or even as good as the 375 under all conditions and with my style of hunting? Nope