ALTERNATE TARGET
ENGAGEMENT TECHNIQUES
by SOF WO1 Michael Haugen
Before we can discuss various
sighting techniques we must first discuss the terms that are used.
Trajectory: The path
that a projectile follows to a terminal point.
Rising Branch: The
upward flight of a projectile along the trajectory effected by velocity
and elevation of the weapon.
Maximum Ordinate:
The highest point obtained by a projectile along the trajectory.
Falling Branch: The
downward flight of a projectile along the trajectory effected by
gravity.
The first target engagement technique is
Point Blank Zero or PBZ. Point Blank Zero or PBZ also referred to
as Point Blank Range (PBR) is that range for a given cartridge,
environmental conditions and elevation that the maximum ordinate
of the trajectory does not rise or fall outside the dimensions of
the desired kill zone of the target.
Hunters use this technique all the time.
At the beginning of the season the hunter zeros his rifle at a set
distance. He knows through experience that should a deer appear
anywhere from his muzzle to the range he zeroed he can engage it
without altering his point of aim. What this means to a sniper is
that he can index a specific elevation on his weapon and engage
targets out to a certain range without having to make any elevation
changes. For a military sniper using a rifle chambered for .308
(7.62mm x 51mm) he can set the elevation to 300 meters and engage
targets from the muzzle out to approximately 375 meters without
changing his point of aim (POA) (when aiming center mass) or his
elevation and strike the target within (+/-) 6 inches of that POA.
This is very effective and useful when conducting defensive, offensive
or retrograde operations.
In order to understand PBZ one must understand
ballistics and trajectories. A bullet does not fly straight to the
target, rather is establishes and arc rising from the muzzle (rising
branch) to an apex approximately 2/3 of the distance to the target
and then falls towards earth (falling branch). In longer ranges,
the bullet will pass the line of sight on both the rising branch
and falling branch. See Figure 1.
PBZ is taught by military sniping schools
by a defined range and elevation. However, this technique can be
adapted using any range/elevation.
You can see that the PBZ runs from the muzzle
to the target. In reality it would run past the target a short distance
depending on range and elevation. Shorter ranges will have the PBZ
as depicted above, whereas longer ranges will have an area that
can be used as a PBZ on the front and back end of the trajectory.
When there is an area on the front and rear of a trajectory that
the round does not rise above or fall below the kill zone, it is
referred to as Danger Space. Danger Space and PBZ are technically
two different things however both can have the same use. They allow
the shooter to affect targets using the trajectory of projectile
without changing his elevation. Danger Space will be discussed shortly.
Shooters can use this technique with any
elevation/range combination by knowing what the maximum ordinate
(max ord) is of the chosen round at any given range. Examples of
this for the .308/7.62 NATO are the 300-meter PBZ and the 500-meter
PBZ. For the 500-meter PBZ, the shooter indexes 500 meters on his
sights, the 7.62 has a max ord of 2.4901 feet along this trajectory.
So the shooter knows the if he has 500 meters indexed on his gun
and a target appears at 375 meters if he holds center the round
should impact approximately 2.5 feet or 30 inches (approx. 10 MOA)
high. So looking at the target the shooter can instantly hold the
waist or crotch and shoot the target. Also, should a target appear
past 500 meters but closer than 600 meters the shooter can just
hold neck/head and fire. About this point most people are probably
thinking, "this is just Kentucky Windage". Thats
exactly what this is only with more science applied.
Another alternate target engagement technique
is Mil Hold Offs. This technique uses the same principles as PBZ
but the shooter is compensating for range adjustments through the
mil dots. Figure 3 shows Hold Offs and how they are used.
Its must be noted mil hold Offs are NOT very
accurate. This is especially true at ranges over 600 meters. The
700-meter and the 800-meter hold off should only be used in an
emergency. However, when there isnt time to mil/range the
target/s or there are many targets, mil hold Offs can prove to
be very effective in the suppression of targets.
The next technique is Danger Space. This
like many aspects of long range shooting is usually misunderstood
and rarely used. As stated, Danger Space (DS) is that point along
a trajectory, which the path of the bullet does not rise above
or fall below the kill zone of the target. What DS really equates
to is the range error that is affordable when estimating range
to the target. If the shooter sees a target that he believes to
be around 700 meters, he must correctly estimate that range to
within 38 meters of the actual range. Meaning that if he decides
through the use of mil dots or laser range finder, etc. that the
actual distance to the target is 700 meters but it is actually
650 meters (+/- 34.5 meters, DS for 650) he will completely miss
the target, the round will go over its head. This makes the spotters
job that much harder as he probably wont see the splash or
trace. The point here is that the shooter must know what his DS
is. He can use it to his advantage. Where this really comes into
affect is that is allows the shooter/spotter to spend less time
arguing about the actual range to the target.
There are basically two ways to find out
what the Danger Space is. The first is to acquire pre-printed data
that identifies the DS. The next method is to purchase one of the
programs currently being sold that will calculate the DS for you.
The key point to any of these methods is
accurate range estimation. Without this the shooter has no way to
know if he will be able to hit the target or not. Another thing
that should be noted is that if you are shooting at longer ranges
(500 and beyond) just take the time to accurately estimate the range,
dial it on and engage the target. Notice that none of the above
techniques dealt with wind corrections, this is another factor will
greatly affect hit probability.
Lastly, every technique requires practice
and experience. You cannot gain either through reading, you must
shoot. So, save your money and buy ammunition, go out to a range
every opportunity you get and shoot. Remember QUALITY NOT QUANTITY.
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