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The importance of group centering.
Part of the guru grumbles.
A question, do you know that every time you wind the sight, you alter the
actual group centre?
It is crucial to ensure that the group is centered, and I reckon there are a few
reasons to shoot at the "Fat part". The main one is to be able to take
advantage of the size of the group by giving yourself the maximum area to
play around in on the bullseye.
As we are aware, with the capabilities of the gear, and the ammunition far
exceed the limitations of the measurements of the V bull and actual bullseye
of our targets. The shooters of West Wallsend are very capable of shooting
possible scores at any of the ranges back to 1,000 yards, and if the group is
centered correctly, usually results in quite high V counts.
These high V counts are not an accident, they are reflections of the
In coached matches, where the wind coach has control of the group centre, I
think it is mandatory to ensure the wind and elevation knobs on the sight are
used to maximise results.
The question above is very relative. Every time the knobs are twiddled, the
group centre is adjusted, and it often takes five or six shots for this to become
apparent on a plot sheet.
My work with the State and National Teams has left me extremely aware of
how important this is, and of far more importance is the relative consistency of
the wind zero’s of the respective rifles used by the members of the various
teams. In a team situation, where there are 5, 6, 10, or 15 shooters, you
would be surprised at how consistent the group centering becomes when
every shooter has virtually the same numbers on the wind arm!
It is crucial in a team to have correct wind zero’s, and to know the exact
elevation numbers for each and every shooter for each and every distance,
including the ranges we are shooting on.
This is one of the ways to maximise the ease of centering the group.
I would like to point out the high V count of the Westy team when we won the
Josephson Teams match with a record score recently.
This was a product of an easy weather day and the group centering of the
respective shooters. I have had a good look at many of our team plots over
the years, and it is significant that, at the Joso teams that Sunday, because of
the easy day, the groups were centered smack in the middle.
(As a foot note here, because of the easy day we were able to discern that
one of our shooters had a dysfunctional rear sight.) This became obvious
when the plot sheets were analysed later.
In a wind coached situation, there are times when the group centre is adjusted
to ensure that shot loss doesn’t become shot loss. The errant wind read shots
may still be contained in the bullseye. This factor is decided when the wind is
changing to velocity increase and so the higher wind velocity shots remain in
the bull because the group is adjusted off centre a little.
There are a number of methods used with the wind knobs. One of these is to
shoot quite fast, and adjust the shots by the position of the spotting disc in the
V or Bullseye. Irrespective of this method, you are still adjusting the group
centre every time the knobs are wound. I saw Owen Pattinson win two
Queens with this method. He shot them down there quite quickly, and if the
spotters were moving to the sides or edge of the bull, he wound the sight and
moved them back in. It worked well, and still does if you want to pursue the
method. The clue is to shoot very fast with this method.
In all cases, you have to know where you fired the shot. It is important to
nominate the shots to yourself and have the courage of your convictions.
It is obvious that if you shot a sudden 12 O’clock inner from an otherwise
good group, and then moved the elevation down, you stand an extremely
good chance of shooting a 6 o’clock inner for your next shot. Particularly if
the previous series of shots were good ones! This is a facet of accuracy
called error chasing, and I have seen many a shooter get into strife with this
problem. Like I said, you alter the group centre when ever you move the sight.
Every shooter I know has a cone of hold. Some of them can easily hold the V
ring and better at any distance. Some of the elite shooters I know have
extremely small group areas and can thus play around inside the central bull
at their whim, adjusting the sight to retain the V bull as the shoot progresses.
Conversely, there are those around (and some of them quite good shooters
too) that can only just maintain a group size inside the bull or even the inner
ring. These are the shooters that MUST be able to adjust the group centre all
the time, otherwise, at some stage they will shoot the occasional inner purely
because it was difficult to adjust the group centre. These shooters find it
increasingly difficult if there is some wind about. Some of them get frightful
beltings, yet quite often you can see their scores come up to very high levels
when shooting under a capable wind coach.
On difficult ranges, such as Canberra, where the wind changes are usually
quite fast, it is often required that you move the wind arm back to zero and
decide on the wind value out there before the next shot is released. Can you
now see how important it is to have the wind arm correctly zeroed?
Canberra quite often has wind changes that result in crossing the zero line, as
do many other ranges depending on the prevailing weather conditions.
In cases like this, it does not hurt to use the sighter shots to determine the
extremes of wind value as this can give you a very good heads up indication
of the adjustments to use in centering the group.
I saw a Queens won in New Zealand in 2001 where the shooter returned to
zero then made the adjustment he thought was needed. John Whiteman won,
but more importantly shot the whole Queens week over Trentham without
losing a single point! He took advantage of his knowledge, but had the
courage to back it up. His attitude was incredible, and this too became an
integral part of his commitment to what he was doing.
Group centering is extremely important, and for next Grade, which starts in a
couple of weeks, I would like to see a plotter sitting up there with Alan
Seaman. The State Team, National Team and the various Sydney teams all
use the extra man on the plot sheets. This allows the coach a free mind to
concentrate on his job. It can only benefit the team, and we should give this a
lot of thought, as part of the plotter’s mandate is to ensure the group is
Last Modified - 12:11 8 Feb 2008