A
Look at Mil-Dot & Ballistic Reticle Scopes for the Savage 10ML-II
The
basics of a Mil-Dot scope at the “Mil-Dot calibrated power” (normally
10x or 12x in hunting scopes, sometimes noted as just the highest
power in scope instructions) is simply this: dot to dot means
about 36” @ 1000 yards, or 3.6 inches at 100 yards. Few instruction
manuals that accompany Mil-Dot scopes go into useful detail at all.
I say “about” 36” at 1000 yards, because it is closer to 36.000012
inches but that is more extraneous than useful. The measurement
here is milliradians of angle.
There
is an important distinction to be made; there are two common ways
to measure angle. We have just touched on “mils” or milliradians,
but more common is MOA—meaning minutes of angle. It can get confusing,
but if the goal is accuracy, we need to be sure if milliradians
of angle are being discussed or minutes of angle. Like metric versus
English units, it is just two different ways of defining measurements.
There are 360 degrees in a circle which translates to approximately
6.2831853072 radians in a circle.
Most
range-finding or range-compensating reticles, like the ballistic
plex style of reticle, are based on minutes of angle. This is whole
different ballgame, as we can forget about radians and milliradians.
One MOA equals about 1.047 inches at 100 yards. A 3 MOA ballistic
plex reticle is 3.141 inches from line to line at 100 yards, 31.41
inches at 1000 yards. Not enough to fret about at 100 yards, but
as both of these scopes are marketed as long range sighting systems,
assuming the wrong way a reticle is calibrated can cause you to
miss your varmint at extreme long range, frustrate you, or both.
The whole point is accuracy to begin with, so we might as well be
a bit accurate as to how this stuff is supposed to work from the
start.
Mil-Dot
scopes, once you get the hang of them, are far more versatile reticles.
You can holdover and hold under with equal ease, and precisely allow
for windage as well. With dots all over the place, it is very easy
to visualize half of a dot to dot length, or a dot and a half of
length as the case may be. Mil-Dot aficionados will tell you that
a Mil-Dot scope is the only “real” range compensating scope (and
range finding scope) that there is. Well, they have a point—or
at least a dot!
However,
there is an advantage to the big game hunter and the long-range
muzzleloading hunter specifically in choosing and using a more simplistic,
albeit more limited design. A ballistic plex type reticle does not
clog your field of view like a Mil-Dot, and hunting reality shows
that in the vast majority of cases, neither high magnification nor
holdover is used to take game animals. In this large majority of
cases, neither a Mil-Dot or a ballistic plex style is used or of
any value. Many feel that if you are a casual hunter, you are wise
to limit yourself to the maximum point blank range of your rifle.
As for closer being better, well—it just always is. Use of a ballistic
plex reticle is out of the way when you don’t need it, but instantly
there on the rare occasion when you do. It sure beats the notion
of “good old Kentucky” at 300 yards, more art than science. We can
also discard the 3.6 inch way of thinking for practical purposes,
and just use the more intuitive (for many) 3 inches per hundred
yards of range between the gates, or 9 inches at 300 yards. With
fur in the crosshairs, the less optical clutter the better.
Onto
a specific application and example that will hopefully give this
little missive a bit more meaning. The scope used is a Bushnell
Elite 3200 4 x 12 AO with RainGuard, with Bushnell’s “Ballistic
Reticle.” The gun: a Savage 10ML-II. The load: 60 gr. Vihtavouri
pushing a .458 Barnes Semi-Spitzer (G1 of .291, Form factor .702,
SD = .204), muzzle velocity of 2287 fps.
A logical
true zero is 150 yards. That makes us good to go without elevation
correction to 190 yards, dropping 2.98 inches below line of sight
at that range. At 200 yards, shift to the first tier of our ballistic
reticle. What would put us at -3.99 inches is now actually +2.01
inches thanks to the reticle. Now we are good to go again, but for
a far shorter increment out to 250 yards now at (2.5 x 3 in.
= 7.5 in correction subtracted from LOS of -10.82 in = -3.32).
Between 200 and 250 yards, tier one does it for us. Beyond 250,
we need to shift gears again: down to line two of our reticle. That
is 6 x 2.5 = 15 inches correction at 250, a line of sight basis
meaning +4.18 inches at 250. We shift to this 2nd line only past
250, though—and we are trajectory corrected again to 300 yards,
where we find ourselves at -2.69 inches. We’ve not yet addressed
windage, but that is a story for another day.
After
300 yards, things get ugly in a hurry. At 310 yards, we will drop
to the third tier. That gives us 9 inches x 3.1 = 27.9 inches of
compensation. Calculated from the -23.05 LOS, we are +4.85. We can
continue to 350 yards leaving us at -2.55 inches. Beyond this, we
have exceeded the ability of most to accurately place a shot, and
the .45 caliber trajectory (and windage) makes continuing
a marginal affair for most. Our bullet drops over 3 inches from
350 to 360 yards alone, and over 3.3 inches in addition to this
from 360 to 370 yards. At 370 yards, just a 10 mph crosswind blows
our bullet nearly two feet away from our crosshairs on a stationary
target.
So,
though all this must naturally be 100%
range verified in your individual gun to confirm, the
thought process with the 150 yard zero and the Bushnell Ballistic
reticle is this:
Inside
200 yards, take him. Between 200 and 250, use the first line beneath
the crosshairs. Between 250 and 300 yards, the second line does
the proper vertical compensation. Between 310 and 350, the third
line does it.
With
this reticle, briefly—the length of the lines compensate for 10mph
wind drift in concert with the specific tier you are on. Tier one
has 3 minutes to the left and right of the vertical crosshair, tier
two has six minutes on either side, and tier three has nine inches
on each side. Co-mingled with the first line above, at 200-250 yards
we can easily compensate for a 10 mph cross. Beyond that, I believe
you’ll need a printout and a windmeter to have confidence in the
shot—best bet is no crosswind at all.
With
this load, a 175 yard zero is an easier way-- at least for me.
+2.46
@ 100 yards
+/-
0.0 @ 175 yards
-3.13
@ 210 yards
No elevation
correction inside 210 yards.
+2.31
@ 220 yards using first line of reticle
- 3.73
@ 270 yards using first line of reticle
beyond
270 to 310 yards, use 2nd line holding on the spine.
Not
a bad general purpose load. In fact, I think it is an outstanding
one.
