In gentlemanly debate, much as the internet allows anyhow I’m concerned you have a hypothesis that you can’t bend on, and are unwilling to move from the set of rules you believe apply universally.
From what I saw over the years here, Africa and elsewhere in outfitting and culling SD would rank as the least important factor aside from diameter with modern bullets. I believe it was more important with past overly soft, non-bonded bullets with soft lead cores, or where FMJs / solids were relied on for penetration alone.
In the proportion of the game shot that came from outfitting, distance travelled after the hit was paid great heed as you don’t want a mountain goat moving lest it become unrecoverable, or a grizzly hiding wounded. For a time I attempted some measure of scientific method of paces taken after the shot, but that really doesn’t work with mountain goats and was abandoned. The patterns became very clear to even a casual observer in the end, and my head guide preferred .270 WSM for everything. He’d seen a lot of hits in his career.
With grizz your headspace was often elsewhere if they were out of sight. In the end, it became extremely apparent the least important factor was SD, the most important was a good bullet arriving fast. SD did have a corollary effect that only really surfaced after 300-400 yards in that higher SD relates very closely to higher ballistic coefficients, and meant more retained velocity (energy).
In the end a .30 cal premium 130gr outperformed a 175gr 7x57 routinely which was my main client loaner. Early on I loaded 175s, later I switched to 140gr premiums with significantly improved effect on game. This was inconvenient for my beliefs as I’ve said before here, I went in believing in heavy for caliber and moderate speeds, and left having to accept speed (energy) kills best, long as the bullet construction is up to job. And so many are these days.
I used to wax about SDs of .300 and speeds around 2300-2500 for years ten to fifteen years ago, in the end that was utterly trumped in experience and now I only advocate for a premium bullet arriving at the animals at 2200fps minimum, and ideally 2400fps or better. Cartridges capable of 3000fps at the muzzle make that far easier, and were more effective in the field in BC where ranges stretch long and animals to move after the hit become highly problematic. My favourite guns to guide, the .300s, I much preferred seeing a lighter, faster premium in that an 180 or 200gr range.
The least impressive .300 effect I witnessed on grizz were on longer shots with stiff 190gr bullets on a pair of grizz, one happening to be my own. It got in a river and died swimming in a stiff current, and made for a bit of a rodeo retrieval. When I worked it back, those bullets arrived around 2000fps, when I saw similar bullets land closer and faster on the same game, the effect was significantly more immediate. Consistently, low SD bullets of modern construction penetrated completely, and no more could be asked of them in that measure.
