HUNTING
How do I determine the
accuracy of my firearm?
To shoot a 3-shot grouping at 100m, with the shots cutting one another, must certainly be an
indication that my rifle is accurate. But is it the only way of determining the accuracy of my
rifle?
By Jan-Lodewyk Serfontein
Hunting expert
I
n reality it does not happen very often
that three shots cut one another on
your target. The setting of your rifle
can be 100% accurate, with perfectly
reloaded ammunition, and it can hap-
pen that the desired grouping cannot be
achieved on a given day. This may be due
to external factors affecting the trajectory
of the bullet, which push it away from its
target.
In addition to external factors such as
wind and temperature, a number of other
factors also affect the accuracy of your
rifle. The technique of a shot is a determin-
ing factor in finding the target. The tech-
niques to be mastered by a shot include
the way of pulling the trigger, cheek posi-
tion and dealing with the kick-back action.
Should these variables not be dealt with in
exactly the same way every time, your rifle
will not be accurate.
Poor quality telescopes and shots
with weakening vision, can also be deter-
mining factors in the accuracy of a rifle.
Telescopes play an important role in the
placement of a bullet. In addition to the
importance of being able to see what you
want to shoot, the telescope also has to
be accurate. The cross-hair of an accurate
telescope does not move around by itself
and has to be set accurately if necessary.
Due to the fact that a barrel which moves
0.016 degrees away from the target will
result in an inability to shoot an inch group-
ing at 100 paces, it is important to have a
very accurate telescope.
If the external factors and the technique
of the shot have such a huge effect on
accuracy, there has to be another way in
which to determine the accuracy of a rifle.
With technology improving everything,
including rifles, there has to be something
that we can use to determine the accuracy
of a rifle.
In an article published on the website
www.6.5Guys.com on 20 June 2015, titled
Load Development (Part 1 of 2), the writer
explains how he approaches load devel-
opment. One of the ways used by him to
determine an accurate load, is to measure
the speed of every shot and to use the
load in respect of which speed has the
smallest extreme distribution. The extreme
distribution of speed of a group of load-
ings is calculated by deducting the lowest
speed from the highest speed. The result
is then the extreme distribution of speed of
a specific load. The article mentions that
the targets which have good groupings,
compare well with the loads with very low
extreme distribution in respect of speed.
Can we therefore use speed as an indica-
tion of accuracy?
The speed at which a bullet leaves the
barrel of a gun, is determined by internal
ballistics. Should the internal ballistics of
two bullets be the same, they should find
the same target should the technique of
the shot and external factors not be taken
into account. The speed at which a bullet
leaves the barrel of a gun determines the
trajectory of the bullet. Should every tra-
jectory be exactly the same, every bullet
should find the same target.
Before simply accepting that speed
is a good indication of the accuracy of a
rifle, we have to test it. If possible I should
measure the speed of my rifle during load
development. The speed which I measure
is for purposes of determining the tra-
jectory and not necessarily to determine
whether speed and accuracy have a direct
correlation. After load development I found
that a loading which does not group well,
does not have an extreme distribution in
speed of more than 10fps. Therefore, I will
have to do a test to determine the correla-
tion between speed and accuracy. I will let
you know of my findings!
SENWES SCENARIO | WINTER 2019
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