M4 Iron Sights
To adjust
elevation using the factory M4 iron sights, rotate the front sight using a sight adjustment tool, multi
tool or the tip of a bullet. To
bring the point of impact up, follow
the arrow markings on the front sight base. Up will be clock-wise and down
counter clock-wise. Each indent or click on the front sight will move the Point
Of Impact or (POI) by 1-inch at 100-meters.
To adjust windage
using the factory rear A2 sight, follow the arrow markings on the right side of
the windage knob. To move the POI to the right, turn the knob clockwise. To
move the POI to the left rotate the knob counter clock-wise. Each click of the
windage knob will move the POI ½ an inch at 100-meters.
The Group.
The pattern
formed after firing is known as the group. The center of the group is known as
the Mean Point of Impact or (MPI). In order establish a group, the shooter must
fire a number of rounds consecutively without changing positions. Typically 3
rounds are used during the initial stages of the zero. By firing only three
rounds, shooters can conserve ammunition while making bold adjustments to
windage and elevation. Once the group has been moved to the desired location,
the shooter should fire a five-round group to confirm that the zero is correct at
that range. Firing five rounds will highlight consistency in marksmanship and
will also expose any inconsistencies with fundamentals during the firing
process.
For example, if
you only fired three rounds and one round was separated from the other two, it
could be assessed that the separated round was a flyer, an error created due to
poor fundamentals. However, if another two rounds were fired and were grouped
together with the single round (flyer), the group would then read as if the two
initial good rounds were the inconsistent ones. This is known as a split group
and the firer should fire again. Split groups are difficult to assess and an
indicator that the firer moved the firing position in between shots or adjusted
position midway through the group.
Moving the Group.
Following the
manufacturers guide will give the shooter the best results when making
adjustments to the sight during the zeroing process. The shooter must determine
the center of the group or, the Mean Point of Impact or (MPI) before making any
adjustments to the sight. If after firing the first three round group it is
determined that the MPI is a long way from the desired zero point, the shooter
should make bold adjustments, using the manufacturers guide to move the group
in the general direction of the zero point. Once the shooter is in the vicinity
of the zero point, he can then use fewer click adjustments to make fine
movements of the group until the correct zero is achieved. Remember, the value
of the click will be reduced by three quarters when zeroing from 25-meters.
Therefore, if the value of each click is 1-inch of movement at 100-meters, the
value of the same click will be ¾ less or ¼ of an inch at 25-meters.
Zeroing Practical
The Zero Process.
50m-200m Zero. To achieve a 50/200-meter zero, the MPI of the shot
group will be 1” low of the aiming mark at 25-meter. When using the Redback One
Zero target the shooter will use the solid 1” square of the lower left or right
zeroing target as the Point Of Aim or (POA) reference at 25-meters. The POI
should be center of the hollow 1” square directly below.
Extreme Spread.
The group is
measured from the center of the furthest apart shots in the group. The distance
between these shots is known as the extreme spread or (ES). The ES at 25-meters
should no more than 1.5-inches. This represents the minimum marksmanship
requirements at 25-meters.
Zeroing.
When zeroing is
performed at a reduced distance, it is important to confirm the zero at each
zero distance. The first distance will be at 50-meters. When using the Redback
One Zero target, shooters will use the lower bullseye target to confirm at this
range. Groups should be Point Of Aim / Point Of Impact at this distance. Minor
adjustments may be required for some shooters. The ES at this distance should
be no more than 3-inches.
After the group
has been assessed, the shooter should then move to the 100-meter line and fire
(3) deliberate (10) round groups for marksmanship purposes, breaking and
resetting the firing position between each group. This will establish a Central
Zero Point (CZP), or true zero of the weapon. The CZP should be approximately
2” above the POA at 100m. The ES at this distance should be no greater than
6-inches. This represents the minimum marksmanship standards at this range.
By performing
this process shooters will become more confident in the performance of the zero
between 0-100m and understand the trajectory of the bullet during flight.
The following
picture highlights the trajectory of the bullet and where it intersects the
line of sight at 50m and 200m. This picture is not to scale and should be used
as a guide only.
Confirmation of Zero
The shooter must
move to the 200-meter line and confirm the zero is correct and can accurately engage
targets at that range. An automated range with monitor to reference shot
placement is preferred. However, is this is not available; using a butts-party
to identify impacts can be used.
As an alternate method, several steel reactive targets can be placed at
the berm. The shooter can engage the steel targets to receive instant feedback
of hits. This method is relatively crude, as it will not allow the shooter to
determine exact accuracy. Using a
paper target with a contrasting aiming mark will allow the shooter to fire an
accurate group and move down the range to check zero.
Remember
Accuracy is based
upon three key factors.
1.
The
weapon system,
2.
The
ammunition,
3.
The
firer.
When selecting a
weapon, the purchaser should take the following into consideration.
1.
Reliability.
The weapon selected should meet or exceed military specifications of
reliability. There are many articles posted on this subject on the Internet and
end-users should research reliability reports prior to purchasing their weapon.
I choose to use all Mil-Spec parts and accessories for my weapons and ideally,
a complete weapon system manufactured by a reputable military grade company.
2.
Accuracy.
This seems to be a contentious issue these days as there is a lot of
speculation as to the quality and durability of parts and accessories being
offered on the market by the vast amount of ‘black rifle’ manufacturers. Again,
I suggest doing some research on manufacturers to ensure that you are buying
exactly what you thought you were. Accuracy is typically associated with the
upper receiver. To that end, the barrel and the fit to the upper receiver. A
matched bolt can improve accuracy slightly as lock up is more consistent. The
industry standard should be 2 MOA when it comes to the weapon systems accuracy.
Don’t get sucked
into Mil-Spec either. What I mean by that is that the military will always
select a weapon system based on reliability before accuracy. If you are looking
for a super accurate 1 MOA gas gun, maybe a custom manufacturer might be worth
looking into or a very specific military weapons system dedicated to performing
to that accuracy standard.
Ammunition 101.
The second factor
in accuracy is the type of ammunition that the firer has selected to use. Mil-Spec,
Match, commercial are three basic terms that can describe categories in
general.
Mil-Spec ammo is
mass-produced to military specifications and again is designed around
reliability over accuracy. Bottom line with Mil-Spec ammo is that it is capable
of holding a 2 MOA group at 100 meters. This may not win you a gold trophy at
the three-gun competition though.
Match ammunition
is designed for competition and is spec’ed with accuracy as the primary focus.
The projectile is not seated as deep or tight as Mil-Spec ammo so that it
leaves the case more consistently when fired. Most match rounds also have a
hollow point to assist with accuracy. Hollow point ammunition has been a
contentious issue in the military and how or if it violates treaties signed by
the U.S Government.
Commercial grade
ammunition like many rifle manufacturers, produce a range of ammunition that is
designed for the average user. Some make ‘close to Mil-Spec’ rounds others hoping
to bid on military contracts will make to Mil-Spec standards. At the end of the
day, there are some good commercial manufacturers of ammunition that is
suitable for training and defensive purposes. I use a combination of commercial
loads and Military loads with my weapons for training.
When selecting
your ammunition, you should look for a round that is reliable and can produce
accuracy standards of 2 MOA at 100 meters. There is some much to learn about
ammunition and ballistics but these very basic points will help in making
better choices.
The Firer
The firer is
always going to be the weak link when it comes to accuracy. Marksmanship
standards can assist with maintaining quality when it comes to individual
marksmanship. The military holds personnel to a general marksmanship standard
of 1.5-inch groups at 25-meters or 6-inches at 100-meters. I believe that with
a quality weapon and ammunition and some good training, a more realistic group
size should be 1-inch at 25-meters and 4-inches at 100-meters.
Conclusion.
Don’t get sucked
into industry hype about guns, ammo, shooting and accuracy. Unfortunately the
industry is full of companies trying to sell you things you don’t need. Some
are trying to manufacture solutions to problems that don’t even exist! And, outside
of product manufacturers there are the firearms experts who know everything and
can teach you everything you need to know. Well, just like buying a weapon,
make sure you do your research when it comes to selecting a service provider to
train and teach you how to deploy your weapons. In an over-saturated market,
few will prevail. The cream typically rises to the top and those that lean
forward and continue to progress and develop new innovative methods will be
here when the smoke clears.