What is the width, in MOA...


of a standard front sight post?

of the large and small apertures of the standard rear sight?

of window on an Aimpoint optic?

Is there a conversion for scope objective lens size to MOA?
(say a 40mm objective equals "X" MOA?)

MOA width depends on sight radius... further the post from the aperature/your eyeball, the smaller it will be.
Large and small aperatures depends on distance of your eyeball to the hole... no universals for em
Same w/ aimpoint.
W/ scopes, the Field of View is generally given at known distances (100"at 100 yards or w/e)––- it all depends on your scope... Mildots are ~3.4moa apart(at 10x) IIRC...
 

Fair enough, and a good reply.  But it can be given using a "standard sight picture"  because an Aimpoint or EO the dots are a certain MOA right?

The dot itself is a set size, yes,  but the tube's picture size is variable depending on how far the tube is from your eye.   If you hold the aimpoint up to your eye, your FOV is... approaching your eye's FOV, but if you hold the aimpoint at arms-length, the FOV at 100yards might be 5 yards...  see what I mean?––  To find out the MOA's of your FOV w/ur aimpoint will require you to do experimentation and measuremnt taking





As a gross generalization, on a 20" ar15... the standard FSP should cover roughly 35" at 300m or ROUGHLY 10moa...