Hello, all of you

I would like to know your opinion/experience regarding action looseness and its effects over regulation. I have read that a double will not regulate correctly if the action is loose, and in other place(s) that action looseness will not have a measurable effect over it. My theoretical calculations are as follows: Imagine (The Lord will not let it happen...!) that your double has a worn hinge pin, and you have a fore/aft play of, say, one thousandth of an inch betwwen the action and the barrels. With an action width of say 1,5" and a barrel length of 26", the muzzle end of the barrels can move about 35 thousands (the distance between the center of the barrel and the center of the action is less than half the width of the action). At 50 yards, this movement corresponds with nearly 2,5 inches of outward movement of each barrel, or a theorical movement between the two bullets of (aargh...) of five inches more that what the regulator planned. If you fix the rifle and tighten the action, this barrel movement is not more possible, so the double will regulate different (hopefully, as the regulator planned)
Any of you has had some experience of changes in the regulation of a "off face" double after being tightened? What do you think about it?

Thank you

Antonio