Well, I’ll throw in some gack talk that has only a minor relationship to the 7m-08 under discussion.

Placement, placement, placement, then bullet construction. If you put a decent bullet in a vital area any animal on Earth will die. “Decent” meaning it holds together well enough to reach the vitals. If you want to shoot from any angle through any obstruction – shoulder bones, paunch full of food, whatever, use a stronger, slower expanding bullet. If you take only broadside shots and can avoid hitting heavier bones you can use faster and/or quicker expanding bullets, I understand the VLD bullets work very well since they come apart violently after about two inches of travel.

Bullets don’t know what case they’re loaded into. Range turns every chambering into a lesser one. A .300 Magnum at 400 yards is no more powerful than a lesser sized case closer up. And animals don't read energy charts in the first place.

Regarding the .270, it achieved popularity at a time when your average deer/elk hunter was using cartridges that threw bullets at 2000 to maybe 2600-2700 fps and had rainbow trajectories. (Yeah, I know, the 2% of rifle looneys were using Newtons and what all, I’m talking about the other 98%) The .270 came along and threw a cup and core bullet of size big enough to penetrate okay at a speed that would let you miss your range estimate out there at 275-325 yards by several yards and still get a hit. That’s what JOC liked about it. Nowadays everybody has laser range finders so you know within one yard how far the animal is and can hold or adjust your scope accordingly.

We've overcome the range problem but wind is still the long range shooter’s gremlin so high BC bullets that drift less are what folks want now, speed which translates to trajectory is not as important as it once was, that's why a lot of folks like smaller brass bottles since they don't kick as hard in equal weight rifles as those ejecting more powder. But those high BC bullets do the same thing in the horizontal plane that the .270 did in the vertical – they let people misjudge the unknown variable a bit but still get a hit.

Each animal is different, each shooting situation is different. I don’t have any empirical evidence of this but I’d wager the animal’s reaction is different if the heart is in its systolic or diastolic condition (or however that is described) and that reaction still varies tremendously with bullet placement.

Swedes have used a 6.5x55 on everything and it kills them. Some folks use .223’s and .22-250’s on deer and even elk with cup and core bullets and have killed them for years. One guy many decades ago used a .17 Remington on feral donkeys and reported that it killed them immediately – provided he hit them properly.

Placement, then bullet construction. The brass bottle is in a distant third place.

I really wish I had videos of multiple deer and elk being shot at various ranges with any of 5 different cartridges, say from the 6.5 Creed up to a .30-06. Ask people to watch the videos and tell which cartridge the shooter used just by the animals' reactions, distance they travel and time it takes for the animal to expire. I would bet goodly money no one could do it except by random chance.

Learn to shoot. Disrupt the animal’s vitals any way you want and it will die. If you want to hit things far out there, get a range finder and use a bullet with a high BC. That high BC will steer you toward the 6mm to 7mm range since that seems to be a nice sweet spot of velocity/bullet weight/recoil – you could shoot a .458 bullet with an equally high BC at 2900-3000 fps if you had the right twist but your shoulder sure wouldn’t like it.

Some brass bottles have minor handloading advantages over others or the barrel might last 10% longer or whatever reason people choose to rationalize their purchases and stroke their ego identity, but those are gack discussions outside of killing power. Bullets don’t know what cartridge they are fired from.

Learn to shoot accurately. Learn your quarry's anatomy so you can put a properly constructed bullet (and there are tons of them these days) where it will kill them. Everything else is illuminated pixels on someone’s computer screen.

Gunnery, gunnery, gunnery.
Hit the target, all else is twaddle!