On 20 Nov 2008 03:50:08 GMT, "DoN. Nichols"
wrote:

On 2008-11-19, Gunner wrote:

[ ... ]

you would make an excellent student of mine. You got it in the first
go.

Range estimation is the reason.

Range finders can and do take a **** with great regularity. If you
are using a fixed power scope, you can easily, over a short time,
learn to estimate the range, and apply the proper hold over for the
various distances simply by how big the target is in the scope.
Various "sniper scopes" use multiple crosshairs, horizontal lines and
so forth and yes, they can and do work well, but only at one fixed
power. Fixed power scopes tend to be much sharper and can only be
matched by a far more expensive variable. The Shepard and ART2 scopes
are specialist scopes and work well enough with their compensation
mechanics, but are exceptionally pricey and can be a bit fragile.

Hmm ... I can think of a design which would deal with the
problem of the hold-over crosshairs shifting with magnification. Put
all of the zoom optics between the reticle and the eye, so the image
relative to the reticle will not shift.

Of course -- this still leaves you with the problem of
estimating range. (Hmm ... for an upright human of average size, adjust
zoom so foot to head range spans two specific cross-hairs (perhaps add
one near the bottom for the purpose), and then read off the range either
on the zoom ring, or on a display in the eyepiece. It might even be
more reliable than the typical rangefinder for that specific target.

[ ... ]

A personel interdiction scope needs to be rugged, reliable, clear and
have good repeatable elevation and windage clicks, perferablly ones
you can hear AND feel.

Something which I have been lucky enough to never need to deal
with, and which I hope to never have to deal with. But who knows what
the future holds?

Does everyone understand the concept of what "point blank range"
really is, and why is critically important to know what your
rifle/cartridges BPR is?

IITC, that is the point at which the arc of the descending
bullet re-crosses the line of the sights. It crosses it once on the way
up fairly close to the shooter, and from then until the PBR it is above
(but not much above) the line of sight. Then after it crosses at the
PBR, it starts getting progressively worse. :-)

Enjoy,
DoN.


Absolutely correct. And given that the Center of Mass is a large
verticle zone, Point Blank range is a pretty good distance, where you
dont have to hold over..you simply need to be able to place a round in
that area.
Hold at the top of the COM, and for quite a number of yards going
farther and farther away, a round fired will go into that verticle
area.

Gunner