Thanks for dispelling some of those myths.
I have a question on full sizing versus necksizing that you might be able to clear up.
The benchresters I know have spent bundles of $ trying to gain every advantage they can to get the last bit of accuracy.
The ones I know have had their full sizing dies specially made to match their individual rifle chambers. One shooter with two benchrest rifles in the same caliber has even had special dies made for each barrel. And yes he full sizes with those special dies for every reload. He wins his share of local matches so your statement on full sizing has merit.
But the kind of investments that benchresters make in special stuf is foreign to most of us. Just the bolt on one of his benchrest rifles costs more than two of my rifles. Those specially made dies for every specially-made barrel are out of my league.
I'm not sure that kind of full sizing with specially machined dies quite equates to what most of us use for sizing dies so I'm not sure that using benchresters as examples of full versus neck sizing relates to what most of us could do with factory dies that are made, as you point out, for chambers that are designed for the range of factory ammo.
Is there any data that you know of on full sizing with an off-the-shelf dies that shows full sizing is better or worse than neck sizing?
Just as an aside, I have also heard that neck sizing supposedly puts less strain on the cartridge and makes them last longer and get trimmed less. That might also be a myth that you could dispell also.