Well, I forgot to take any measuring instruments home with
me, but did get the rifle with the NECG peep out of the safe
and look it over last night.
To my eye, the larger aperature is somwhere around 1/8",
the smaller 3/32".
After looking at it, I remembered why I side-lined the
project. Adding a small #4 or so set screw to allow locking
elevation would be fairly easy, could come from several different directions, would need to either be brass tipped
or else be careful not to overtighten - I'm thinking bearing
against the dovetail part of the elevation slider would work
best, but wouldn't want to mar it up...
BUT - the kicker is that there is a narrow U shaped groove
in front of the aperature, in the main body of the sight
that in my opionion would need to be enlarged to make use
of any larger aperature than the large one provided.
Doing this would completely eliminate the as-provided
locking mechanism, no going back. And you would either have
to shorten the front of the aperature(s) or else make a
spacer for it, so as not to protrude through front of the
slide. Not a big deal to me, but more involved than I
first thought.
On a side thought, man - do you think they could have built
this thing with any more sharp, square edges on it?
Have been tempted to round off some of them, but then it
will need re-blueing, powder coating, something.