Ratchet column and headspace question

[tacotime]

I read that the height of the ratchet column controls headspace at the breech. But how?

I would have assumed by the ratchet physically pressing against the breech around the firing pin hole, but I don't really see the contact signs and wear on the top of the ratchet lobes or on the breech face around the firing pin. Or maybe it just wears very little because of available endshake. Or what am I missing?

 

[rugerguy]

sounds right, but much of what goes on is when the cartridge actually "fires" and all the pressures back,, forth etc come into play...when just sitting there "in neutral", is different than when in "battery" and different again,, when fired (locked up) actions, and reactions....................
dimensions (blue prints, drawings, patent application drawings to start with) then figure in manufactruing tolerances, and who is building it and how much of a hurry are they in....all the "plus/minus" numbers can drive one batty.........