a3 front sight post

[ssgross]

Its ~6.25 degrees off. Which is indeed enough to notice when looking through the rear sight (drifted .127 left).
For anyone else that finds this, the height of the "A" blade at 1.167 above the bore center.
6.25 degrees is still a ballpark - this assumes the rifle was perfectly level when zeroing and not "canted". But we can figure out that case too.
If it was canted, the rear sight base would have been on an angle. This means the "level" drift of the rear sight would have a lowerbound of cos(6.25)*0.127 = 0.1262ish. Using the previous calculation, a minimum for the amount of cant is ~6.21 degrees.
If you skipped all that, my barrel is between 6.21 and 6.25 degrees over-timed.
My grad. school advisor gave sound advice for presenting mathematics..."never ever do computations in public".
Attachment 114211
so no more than 0.0017361ish increase in headspace.