This doesn't seem like a worthwile argument for either.
You need a load that will cause the projectile to deliver a fast acting, mortal wound. Period. Large and "slow" will do this, as will smaller, and faster....
IF there is sufficient accuracy. THIS is the key.
Once you have a load that will deliver the fast acting, mortal wound at
X distance, for all rounds have a maximum, effective range..., you MUST be able to place the projectile into the animal where it will properly accomplish its task.
My antique tech, patched round ball, 225 grains and .530 diameter, launched at 1500 fps, will go through a deer broadside at 100 yards... and with my iron sighted rifle I can consistantly hit the deer in the heart lung region out to 100 yards. Down they go. It probably has enough energy to destroy both lungs and the heart in a deer out to 200 yards though won't exit the chest cavity, but I can't place a shot there at that range... so I will never know.
One can argue with me that their .223 Remington, or .308 Winchester, .30-06, .35 Whelan or what have you is "better" at 100 yards than my patched round ball..., but the deer fall over for me at my max range or less, the same as for those cartridges. Same results = moot point.
NOW..., say we're talking at an unknown distance... somewhere between 200 and 300 yards..., and add a scope, faster and lighter would be the way I would go. A nice 165 grain SBTHP from my .308 would be what I would use, for it would forgive a lot in my range estimation error, and the scope would vastly help me to place the shot, and I have a scoped rifle in that caliber and very accurate rounds for it.
These discussions, from what I have observed, often stem from some of us in the hunting community that try to make up for poor marksmanship with velocity. I have heard so called "experienced" hunters that swear a .30-30 or even a .30-06 "won't take deer", and a .300 Winmag or a .338 Winmag was needed, although the shots being discussed were no more than 100 yards in some places and no more than 300 yards in other places... clear, no brush, and in Pennsylvania vs. whitetails.
For whitetails:
My late grandpa loved his .30-30
My Dad loves his .30-30 but for pronghorn and elk out West, he used his .30-06.
One of my neighbors is an older fellow who loves his .44 mag, Ruger semi-auto.
Another neighbor swears by his .25-06, and another absolutely adores his .243.
One fellow at the gunshop loves his .270, and another won't use anything other than a .35 Whelen.
I don't use anthing other than my .54 flinter with a patched, round ball.
In EVERY CASE these fellows have found a rifle and cartridge load combination that is very accurate
at the distances that they hunt. The most devastating round ever invented means nothing if you miss.
So while it might be interesting to discuss, bottom line if my rifle goes BANG and the deer falls down, and your rifle goes BANG and the deer falls down, we both have venison (and maybe a trophy mount) and a good story..., why is there an argument?
LD