This is a recreation of Paul Howe's excellent article on carbine zero's, it has been transformed to make it easier to load/ read on a forum. It is hosted here with his permission. The original file is available for download here, complete with full resolution pictures:
The Battlefield Zero
By Paul Howe
I have heard many explanations and thought processes as to the best "Battlefield Zero"
for the M16/M-4 type weapon system. Some explain how the knobs should be turned and
the sights flipped to best accommodate hits. Some of these explanations require a college
degree to decipher. Others use graphs and charts to justify their claims. Nothing confirms
a zero like walking the actual ground and checking the hits on your target. So put away
your graphs, charts, knobs, etc. and let's look at some holds and shots.
For the record, I zero at 100 yards….
Weapon and Ammo:
Rifle: Rock River
Sights: Iron (CSAT Rear/Trijicon Front with tritium insert)
Ammo: 62 Grain American Eagle FMJ/55 Grain WW FMJ
Wind: Day 1 Gusting/Variable from L-R/Day two was calm
Position used: Prone Unsupported
Rifle Used: Rock River
I make a box using the head template, roughly 6 x 6 inches. I put it high in the scoring
box of a CSAT target to get a high thoracic hit.
DELIBERATE OFFSET OF 3" HIGH WITH MY SIGHTS:
At 100 yards, I adjusted my sights to hit about 3" high or 3 click up on my rear dial
from where my front sight cut the target. 100 Yard hit are marked in the center of
- 75 hit a little lower
- 50 a little lower
- 25 cut the line
100 Yard Point of Aim/Point of Impact
My zero here was to have the bullets cut where my front sight post met the target. The
group dropped a little lower than the offset method from 100 yards and in. No real
change in overall group.
3"OFFSET AT 200/300
Here is where the real difference can be found in the zeros. Out to 200 yards, you
hit about the same. At 300, you drop from 4 to 12". Remember, this is the built in
offset and my sight picture was consistent at the base of the box.
POA/POI at 100 caused me minor problems at 200/300. It dropped a bit more at
200 and 300 was significantly low. Normally I hold on your shoulders or face when
shooting 300 with this zero.
Also, my eye was getting fuzzy by this time, trying to see the small box. It was fading
out at times.
Head Shots at 100 with the offset was easy to see and deliver
POA/POI works, but I threw one. As a side note, you can do a center hold, but your
eye may have a problem going back and forth to see how much black you are
dipping your sight into. This may cause eye strain. Using a 6 o'clock hold, you can
simply lollypop the head on your front sight.
Deliberate Offset Method (3" high at 100 yards)
- The deliberate offset method gave me reliable hits out to 300 with the same sight
- At 100 on a head target, I would simply hold on your chin and get a center mass
hit in your melon. If you were prone, I would simply aim where your head and
Point of Aim/Point of Impact Method
- Gives you accurate hits to 100-200 yards
- Falls off at 300
- At 300, I know to hold on the shoulders
I prefer zeroing and training at 100 yards for several reasons:
- It makes you a better shooter
- It is a realistic distance for combat and the capability of your weapon
- It gives you a versatile zero out to 300 yards with a realistic expectation of a 1st
As a side note, I have never had anyone come to a Tactical Rifle Instructor or Tactical
Rifle course with a 50 yard zero and shoot it across my standards or ranges. All had to
adjust their sights. Many did not know where their round would strike at 100 and
I first picked up this term in my time as a sniper. That is having a zero and knowing your
hold offs for targets within the appropriate range of your weapon. This is important to
know for combat.
You need to learn how to shoot iron sights. Above is a picture of an Aimpoint T-1 that
was hit with a simunitions round during training. This could have just as easy been a
bullet, shrapnel, debris, mud, etc. You need a quick release mount when using optics and
I suggest that you co-witness them with your iron sights. Reference optics, my favorites
are the Leupold CQT and the Aimpoint T-1.
Establishing reference points for consistent shooting is critical for consistent accuracy.
These "index" points will transfer to weapons with optical sights.
I have witnessed optics fail in competitions, training and combat. In one law
enforcement situation, a battery powered optic failed and the officer killed a bad guy with
his iron sights five minutes later. In combat I have witnessed soldiers with optics that
clouded up with moisture have to pick up a new weapon because they could not get the
optic off and could not see through it.
It is criminal that the U.S. Army is teaching basic training recruits to shoot with
Aimpoints and no iron sights. They are going to get soldiers killed or other Army units
will have to retrain them sometime down the road.
I have developed a combat sight that allows you to shoot 0-300 yards and beyond if you
know your weapon system. In the above sight, you use the notch at 7 yards and the peep
beyond 15. I try to keep it simple.
Also, I mark my windage and elevation knobs with a paint pen to know where my zero is.
I can view these marks as part of my pre-combat inspection of my rifle.
The sight radius on your weapon does have a significant impact on your weapons zero,
no pun intended.
The top weapon has a mid-length hand guard and about two-inches more sight radius. I
believe this additional sight radius helps the accuracy of iron sighted shooters.
Some of the improved accuracy you find in the various M-4 weapon systems is due to
barrel length, some is due to increased sight radius. I compare it to shooting a short
barreled revolver. In the past, some agencies required officers to shoot 50 yards courses
of fire with a snub nosed revolver. Many did it. What it took was many hours of practice
and the officer doing the same thing every time when behind the gun. An officer with
less trigger time and experience could make the same hits with less training time by using
a longer sight radius on a four or six inch barreled revolver. The sight radius of these
guns would help them out. The same applies to rifles
Zero's and Results
Through these series of pictures, I am attempting to show how I zero and my groups out
to 300 yards using iron sights. I hope I have simplified your understanding of this
process. There is little magic to it and it works.
The above groups were fired using WW 55 grain FMJ. The top group was using my
AE 62 Grain zero from the day before. I had to come down four clicks and left four
clicks on my rear drums to get my groups to center up.
- If you change ammo weights or manufacturers, re-check your zero. It will
change your zero.
The above group was fired using WW 55 Grain FMJ using the 100 yard 3" offset on
the sights. My 300 yard group was a bit spread out because I was taking too much
time going back and forth with my eye to the target and the sight, trying to fine tune
This group was fired using POA/POI WW 55 Grain FMJ. I threw one out a bit at
200, but I am happy with my 300 yard group. In this string, I took my first best
sight picture and pulled the trigger without trying to over focus on the target.
Generally, your bullet drops two" inches at 200. Your eye cannot see this.
I do occasionally shoot optics and have some that I like and us. When I do shoot them, I
have them co-witnessed and mounted with throw lever mounts whenever possible should
In my experience of fast moving combat, I never had time to turn knobs or flip sights. I
had to use what I had on the gun for the shot required. The window of opportunity opens
and closes in a flash and you either make the shot or you do not. You might have time in
a static position such as was found in WWII, but not in a fast moving urban environment.
Further, you now have a light caliber weapon system that requires more accurate hits to
put the target down in a rapid manner. In this case, you must know where your bullet
strikes to do this.
Finally, in my former special operations life I learned that you might get a full body shot
on one opponent in a gun fight, but as soon as you shoot them, their friends will take
cover and probably only give you a head or weapon system to shoot at. I used to make
team members practice shots on full and partial targets at 100 yards and beyond. This is
reality. Bad guys use cover as we do. You must be able to hit them when they get small.
I hope this helps answer some questions and if you have any, feel free to e-mail me via
my web site.
About the Author
Paul R. Howe is a 20-year veteran and former Special Operations soldier and instructor.
Paul currently owns Combat Shooting and Tactics (CSAT) where he consults with, trains
and evaluates law enforcement and government agencies in technical and tactical
techniques throughout the special operations spectrum. See
http://www.combatshootingandtactics.com for details.