Using the old rule of thumb:

1 MOA corresponds to 1" at 100 yds.
so
1 MOA is 1/1000" at 1/10 yd or 3.6"
and over half an inch (the approx. length of the parallel section on an HPBT)
1MOA is 1/1000" divided by 3.6 x2 or 7.2

About 1.4 tenths of a thousandth of an inch. Small enough for you?

So now it is clear why the bench-rest boys measure things like bullet run-out in the case.
And why they try to get the "slop" of the neck in the chamber down to well-nigh zero.
And why neck sizing your fired case, leaving an ever-so-tiny unsized ring at the bottom of the neck that provides automatic centering of the neck in the chamber improves accuracy.

It's not just nit-picky fiddling around - it really can make a difference - if you and your rifle are good enough.