Bolt fitting question

[englishman_ca]

You are not wrong with your concept, Jon.

The time when you wont get recoil transfer thought the bolt body anulus is when a new replacement bolt head is fitted on an old bolt and there is too much overturn.

An old sloppy bolt head and with its long time mated bolt will always bear on the body, not threads. I guess that the worn bolt threads allow more axial movement and the slack is taken up by the extractor pushing on the ramp on closing.
I've seen bolt heads so worn that they were wobbly on the bolt, 45 degree overturn. But the bolt head would bear on the body.
The rest of the rifle was also tired, I don't think a new new tight bolt head would have helped unless accompanied by a new bolt and receiver.

Tight is good, I agree.

If the bolt head sits tight with a slight under turn, one would have problems installing it into the receiver bolt way. Bolt head and lug have to be able to align.