zero to the shooter?


iron sight
iron sight (Photo credit: YourLocalDave)

I had an interesting discussion with some guys about weapon zero today and the issue of “individual zero” vs “weapon zero”. What I have learned/read over the years is that scoped guns are different from iron sighted guns and both are different from red dot/holo sights.

  • On magnified optics (Sniper Rifles), scope parallax can cause differences in individual zeros depending on how the shooter mounts the gun…his distance of eye from scope..etc.
  • In a perfect world, where all of us use the exact same sight alignment/sight picture, all shooters would be “zeroed” with properly adjusted iron sights. Because there are differences in how we “hold” on target and how we center up irons there are going to be small differences in zero. But as long as they are “close” those differences are not drastic within realistic ranges.

The Army FM 23-9 states that “When standard zeroing procedures are followed, a rifle that is properly zeroed for one soldier is close to the zero for another soldier”, this allows soldiers to accurately shoot with another soldiers rifle if he needs to pick one up.

Zeroing is primarily about aligning the guns sights with the barrel..taking individual differences in sight picture into account to fine tune.

FM 23-9 says:

“the similarity of individual zeros should be emphasized instead of the differences.”

“There is no relationship between the specific sight setting a soldier uses on one rifle (his zero) to the sight setting he needs on another rifle. For example, a soldier could be required to move the rear sight of his assigned rifle 10 clicks left of center for zero, and the next rifle he is assigned could be adjusted 10 clicks right of center for zero. This is due to the inherent variability from rifle to rifle”

Which is something many people don’t realize. When I was a young private I thought for a long time that my “zero” was MY zero and that if I dialed it in on any M16 I was issued I’d be GTG. The fact of the matter is that zeroing is really about aligning the SIGHTS to the gun…not the shooter. If we all held a gun the same way and used exactly identical sight pictures/alignments a zero would be universal. Individual zeroing is really just a “fine tune” when proper marksmanship fundamentals are applied.

  • Red dot sights/holographic sights do not rely on sight picture or eye relief. If a RDS is properly adjusted so that the bullet impacts where the dot lays, that sight is zeroed for all shooters who use that weapon. Any variation with a RDS is based on the shooters breath/trigger control. Of course the dot only represents “zero” at 2 points of the bullets trajectory. With our 50 yard zero that should be at 50 and approx 200 yards. The round will strike below the dot when closer than 50 yards and approx an inch to 1.5 inches above the dot between 50 and 200 yards and then drop off past 200.

Of course time and a beating may loosen up the Aimpoint tubes causing a Zero shift.

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7 thoughts on “zero to the shooter?”

  1. Some interesting comments for the practical shooters as compared to the bullseye shooter crowd.

    I’m not surprised the army feels “… is properly zeroed for one soldier is close to the zero for another soldier…” After all, they want a minute of man accuracy and not the ability to hit the heart’s left ventricle. I’m sure most would be happy to hit the heart. I believe McEwen in Sniper Elite talks about the need to “walk” the bullet on to the target.

    Of course the standards are and should be different between the police and military sniper. My instructors use to tell me that the police sniper is a last resort where as the military combat sniper should be an early option.

    Certainly the distances are different. I would expect the accuracy needed to be different as well. In either case personalizing your zero would be a good and useful thing.

    Since all mechanical things have a tendency to if not outright fail certainly drift from set positions, confirming your zero is the only true way of building confidence in your weapon as well as your own shooting.
    http://tactical-talk.blogspot.com/2013/05/checking-my-zero.html

    I have always found shooting if largely a mental game. Having confidence that your gun goes boom every time you want it to and hits where you point it leaves you free to concentrate on trigger control, reloading, aligning sight and all the other things what have to happen.

    Your equipment doesn’t drift? I think Mr Murphy would like a few words with you.
    Stay Safe………

    1. The heart of the discussion that lead to this post was the belief held by several officers that a person had to be zeroed to the gun. This was in regards to RDS sights on an M4 at the time.

      I argued that as long as the RDS was properly zeroed and wasn’t “out of whack” any officer could use it with very little difference (if any) in zero within the range we would use them. Of course if a weapon was going to be re-issued permanently to another person it’s only good sense to confirm the zero.

      They tried to use examples of how different one persons sniper rifle zero was different from another’s as an example of how it was “the rifle being adjusted to the person”. I pointed out parallax and countered that zeroing is about aligning the sights with the bore not the person to the gun. The real difference in individual zeros is improper sight picture/sight alignment. If we all used the same picture/alignment and good fundamentals we would have a universal zero.

      This becomes important in PD’s that don’t have enough rifles for every officer. The only real way to issue patrol rifles with a reliable zero for any officer using it is by mounting a RDS.

  2. Actually your shot will be high the closer you get to the target. At 50 poa/poi your poi will get higher as you get closer. Think you had a typo. Good article.

  3. Was referring to this. In your post you have the following:

    “The round will strike below the dot when closer than 50 yards and approx an inch to 1.5 inches above the dot between 50 and 200 yards and then drop off past 200”.

    Your round will strike above the dot when closer than 50 yards. At 10-7 yds It will be 1.5 to 2 inches high. If I aim / put red dot between your eyes at that distance my round will strike you in the mouth, not between the eyes.

  4. Just proved your point. That’s what I get for making dinner and dealing with 3 kids and a dog all while trying to read your post. LOL. My bad.

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