Yep. The 6.5 cm is a nice cartridge. I have a Legendary Arms works 6.5 cm and used it for several years as my main hunting rifle. Killed whitetail, mule deer, antelope and pigs with it using 143 eldx, 140 fed fusion, and 140 Berger vld. Killed fine but all the animals ran a ways and in general lived longer than used to with a centerfire. So I have rethought my bullet choice and now loading 120 btips to higher velocity, but not killed anything with them yetThe 270 has a larger frontal area and more impact velocity (generally). I am not sure if that is what he was getting at but those two factors would likely lead to what he is getting at.
I will note that my buddy uses 139 scenars using a load or rl26 that touches 270 velocity and gets great resulrs but I am more conservative loader and generally don’t exceed published loads though I will give the scenars a try some time
Lou