Interesting post.
My views from down under, where we don't really have large animals that warrant a medium bore, but I still have mediums and have used some of them elsewhere. The biggest wild animals we have are wild/feral cattle. The guys in the West Island call them scrub bulls and I've shot a few with the 270 and 30/06. I now have 375H&H, 9.3x62, 35 Whelen, 338 Win Mag and 338 Federal, but don't live close to where the wild cattle are, so I travel to Africa.
375 H&H, I've shot 3 Ele in Zim all body shots with complete pass throughs, and 4 cape buff, 2 in RSA 2in Nam, 4 zebra Nam. All these animals were taken with 350gr Woodleigh fmj and/or rnsn. These were all one shot kills with an insurance shot on the 3 ele and 2 of the buff. The insurance shots were probably unnecessary.
416 Rem, borrowed rifle, good bull ele 57/62, 400gr solid, side brain, one shot down, job done. Insurance shot fired, just for the sake of insurance. I could have done exactly the same with my H&H but didn't have it with me.
338 Win Mag, 20 or more plains game, from giraffe and eland down to springbok and impala. All one shot kills and it's probably unnecessarily powerful for all but, maybe the giraffe and eland. I must note that giraffe have exceptionally thick skin, up to 1.5" (38mm). The 338 seems to have a very sharp/fast recoil, it takes some getting used to. The 375H&H a slower recoil and is nicer to shoot. Rifle weights are about the same 9lb 3oz.
30/06, 15 plains game from Zebra down to springbok and impala. From memory I fired 17 shots, went over the top of a springbok at 250yds, missed, with one and fired an insurance shot on an oryx/gemsbok.
243 Win, 1 oryx/gemsbok, 3 black face impala, 1 jackal, 2 baboon.
22 rim fire 3 springbok and some guineafowl.
My opinion of these cartridges, for African game. The 375H&H, especially with 350gr Woodies, is all I would use for ele, buff, hippo. However, I'll not hunt ele again and probably not hippo. So, it's an excellent buff cartridge. The 416 Rem was unnecessarily powerful, all based on one shot/ele, not a great sample size. I would never own one. The 338 Win Mag is maybe not enough for buffalo or ele, but is probably unnecessarily powerful, with the possible exception of giraffe, for plains game. The one and only eland I've taken, was with the 338 and I could have done it with my 30/06. The 30/06 is a great hunting cartridge and is probably capable of more than most people give it credit for. I used Barnes 180gr TSX for 11 animals and Speer 180gr Hotcore for the other 4. For what the Hotcore are they worked exceptionally well.
This year 2024, I'm going back to Africa and have 4 buffalo booked. I will be taking my Ruger No1 375H&H, loaded with the 350gr Woodies @ 2320fps both ppsn & fmj and my 35 Whelen loaded with 310gr Woodies @ 2310fps, both rnsn & fmj. The plan is, the first buff with the H&H and the other 3 with the Whelen. I'll be able to make, a some what biased, evaluation of the Whelen for buff. However still a very small sample size. I'm also taking some 250gr Speer Hotcore for the Whelen and plains game.
2025 I'm going back, for 2 buff and I'll take my 338 Win Mag loaded with Nosler 300gr Accubonds and 300gr Woodies, both rnsn & fmj. These 300s work very well in theory and on paper, 100yd moa at 2450fps. It will be interesting to see how they stack up in the field, with buff. I'll also take some 225/250gr for plains game.
2026 It will have to be the 9.3, with a suppressor and 286gr.
At this stage I don't really have a favorite or go to, but I'm working on it!
Higgy.