Yes, I think this is the proper forum. You guys know reamers and chambers and such.
I am aware of some benchrest shooters who used to, (it may have gone out of fashion), have a special chamber, mine was a .308S, with a tight neck. The brass was precision outside turned to allow a near-perfect bullet fit but no expansion. Then a fired cartridge could be reloaded at the match by priming, powder fill and literally hand seating the bullet to the ridge left inside the case-neck from not quite turning the entire neck. Is this still considered rational thought? I know it only works with loads well down from maximum pressures or they would fail to chamber due to swelling just ahead of the web. I think the lands had to engage on bolt closing for accuracy. Anyone been there?

You might want to checkout Benchrest Central
The benchrest shooters use chambers so tight that they don't need to re-size the brass because the brass doesn't get a chance to stretch; and also tend to load to a higher pressure than any factory would use. Of course they also don't have to worry about cartridges not feeding and missing a chance at an animal, or having an animal get a chance at the shooter.

Bruce--

I have five rifles that *can* be reloaded without any sizing at all, but it's dangerous to do it on a field rifle. For it to work the neck of a loaded cartridge is less than .001 smaller than the chamber. In very few firings the neck grows in thickness due to brass flowing forward at firing. It's VERY easy to jam a neck and face major problems and possible danger gettin it loose. (Two killed so-far)

The much better way is to buy a Wilson insert neck sizing/depriming die with a sizing insert that sizes to .0015 smaller than bullet diameter.

You can allow .0005 for springback and buy a bushing two time the neck thickness, plus bullet diameter, minus .002.

So if you have a 6x47 with turned necks to .0095 the bushing would be .019 + .243 minus .002 = .260 ..

They're cheap enough to buy several. I'd hate to start a new fad of variations of neck tension for accuracy, but it DOES make a difference.

JBelk,
Amazing the thought some folks have put into the concept. Thanks for the reply, I am printing that one out for future reference whent the chambering decicsion has to be made!
Bruce