My youngest son asked me what I thought the most accurate cartridge was.
Well, in context, I would agree with his OPINION, as I've been to the local gun shop and never saw a 6mmPPC or a 30BR for sale. Much less ammo for either one. It would be similar to asking your Dad, what was the best car ever? I doubt that you'd name some rare Duesenburg that some guy in Iowa built right after he finished the pyramids or a factory five Cobra. No, it would be that 1970 Camaro you had right after high school, the last stick shift you ever owned. And again he was speaking in terms his son could understand, and relate to in a real and physical way. A gun he could hand him and say, here son this is my old Ruger 77 in .222 cal. it's off the self and not some special built custom job but it'll do the job on any squirrel you run across.
I never had a .222, my Dad gave me a British SMLE .303 in 1968 for my first deer rifle. I didn't like it to much it was big and bulky, sold it for $15 and bought a Ruger 77 .30-06 for $95, it had a 4 power weaver scope and I loved that gun, I still have it. I have shot hundreds of coyotes and rabbits with it and 40 or so deer, and six Elk with that gun. So if my son had ever asked me a similar question, my answer would have been the .30-06. I don't think that young man was looking for an empirical answer, in my OPINION, he was just bonding with his Dad.
Besides, tomorrow when someone figures out just how to precisely deliver the exact same amount energy to the ninth degree to each an every round fired, the bullets will all be in the same hole anyway, right?