My ears were burning...
Just on a delay.
From my experiences outfitting what you saw was the results of velocity ranges rather than over / under gunned or bullet choices in particular. The mass of the Cape Buffalo also factors but I’ll get to that last.
Guiding I noticed what I used to say was a drastic shift in performance around 2400fps impacts, I worked back from the ranges shot on my phone’s ballistic calculator and there was an inexplicable phase shift in performance where even small rounds outperformed large ones, when they were fast or used at close range. At 250 yards a .270 could made a .338 look pretty ineffective in comparison, but the .300 Ultras didn’t show the same drop off in effect. I’ve seen the drop off first hand with 200gr .300 Win in ranges from 200-300 yards where they drop below the cutoff on grizzlies, and then saw grizzlies that were absolutely flattened by .300 RUM, 7mm Rem Mag, and .300 Win with lighter bullets and slightly closer. The .45-70 / .450 Marlin range were the least dramatic on game, also explained by velocity in my mind. For awhile I thought what I was seeing was a distinct change in bullet performance / opening at 2400ish, but since have learned more.
Recently I came across a video here from Federal and the FBI’s ballistics lab and autopsy findings. At 2200fps impacts and above, radiating tissue damage (tearing and cellular wall destruction, damage to blood vessels and nerves for instance far from the impact site) occurs from shock waves traveling through tissue that is permanent. Below that velocity the primary wounding mechanism is bleeding out, introducing atmospheric pressure above the diaphragm negating aspiration, and physically destroying organs and the central nervous system. That’s what the .45-70, your .450-400, and arrows use to kill. A .270 or .25-06 will often be far more dramatic as they carry the velocity for radiating tissue damage, and do so for a good deal of range.
Turns out I probably estimated a couple hundred FPS high, but a buffer doesn’t hurt in that estimation. On Cape Buff, we’re just dealing with an animal so massive and sturdily built that the letting light in way of killing of the heavier, slower rounds starts to catch up to the faster ones. Physically breaking bones starts to become really important, and lower velocity, and heavier rounds generally track straighter doing this. Even if it’s only breaking that bone to actually get to the organs. With bears, even the biggest ones this falls second fiddle to the effects of velocity and a bullet that can deliver that energy yet penetrate enough to still do the deed without leaning solely on the speed crutch. A good bullet out of a .270, .30-06, or .300 is prime big bear medicine. Better than the .458 Win Mag, frankly. I carry a .375 as it’s fast enough to stay above the cutoff, and penetrates pretty true from bad angles on bone.
This is my buff, he actually dropped on the spot like he was pole axed, to my .375 H&H well inside 20 yards, impact about 2450fps. I also used another .375 H&H to drop a Wood Bison bull a good deal larger than the Cape Buff with one 20 yard shot. Jon (the PH) said he sees the quickest kills from .375 H&H and .458 Lott, both coincidentally arrive over 2200fps at buffalo ranges, though I put this realisation together nearly a decade later. He himself carried a .375 H&H when it rained (SS) and a .458 Lott otherwise, the one real charge he had to stop was with the H&H. Taylor also noted that the .375 H&H and 7x57 has outsized effect his theory struggled to accommodate, the crux of it is they’re the fast ones in his test / experience group. I do believe the effect of velocity is muted a bit in animals of this mass and construction, and not nearly as important a consideration as on North American game. The rules as I’ve begrudgingly learned them outfitting are speed kills, not absurd speed, most standard rounds make it at most ranges. Your average .30-06 does perfectly, and for a good ways.
From now on, any wildcat I make or rifle I build has to get the bullets to the target above the cutoff at the ranges I plan on using it at. Anyhow, my thoughts from a lot of well dead game.
