each individual rifle will have a different throat depth as well as each different make of projectile will have a different shaped ogive
that's why you should be measuring from the ogive and not the point, what you have explained shows you are getting different lengths at the ogive
what the reloading books give you is a one size fits all sammi length that can be very wrong
the reason I did not think it would be your COAL is because if your round is longer than your COAL you still should be able to chamber the round unless your neck tension is very very high, the bolt should only be slightly harder than normal to close, how hard is it to seat your bullet
you would have heard about guys having there bullet into the lands then opening the bolt and the bullet being stuck in the throat
with that neck tension you wont have that problem
anyway it's sounds like you may be onto a solution, if you use my method in the above post you will get precise measurements
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