Is a sighted-in red-dot sighted-in for everyone??

Discussion in 'Sights, Optics and Lasers/Lights' started by ChiefWPD, Aug 30, 2018.

  1. ChiefWPD

    ChiefWPD

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    I'm working on an article on the police use of red-dot sights. I own several, but my experience level with these optics is still very limited.

    Does anyone know, if, once a handgun (or long arm) is sighted-in using a red-dot optic, is the firearm now sighted-in for anyone picking it up?

    My guess would be, "yes." On the other hand, there may be elements in play which I am unfamiliar with.

    Thanks all!
     
  2. DJ Niner

    DJ Niner Staff Member Moderator

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    IF the shooter who sighted it in and all later shooters are competent shooters (no trigger-slappers), AND if everyone's vision is more-or-less the same/normal, AND if the intended target area is fairly large, then yes. Otherwise, probably not. Especially with handguns, the differences in the ways various users see the sights, grip the frame, and fire the handgun really precludes a precise zero for multiple people.

    Then you have lefties vs. righties...

    But we really need to define "sighted-in" and the level of needed accuracy, here.
    9+10-ring-accuracy on a full-size B-27 at 15 yards? Yes, quite doable.
    X-ring accurate on a 50-yard bullseye (or farther, for a rifle)? No.

    Find 5-10 shooters of varying skill levels, hand them a handgun and/or carbine pre-sighted-in with the dot-sight of your choice, define the shooting position and aiming point, have them shoot at the same size/shape target at a set distance, and observe the results. I'd be interested in seeing the outcome.

    .
     
    Last edited: Aug 31, 2018
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  3. I am Groot!

    I am Groot!

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    I would also keep in mind that uncorrected astigmatism makes the red dot distorted and hazy.
     
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  4. DJ Niner

    DJ Niner Staff Member Moderator

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    An interesting study, by itself, but it really doesn't answer the question you asked.

    You want all shooters with some experience (as most cops would have), and then have them shoot the same gun on the same target with the same aiming point, then check their group locations. I'd guess they wouldn't all be overlapping shots/groups, but they would be close. The question is: is close "close enough"? I'd also guess their shots wouldn't be any farther off-center than if you handed them their partner's iron-sighted duty pistol, and if that is allowed under any current policy, then what you are proposing is pretty close to the same thing.

    The problem is going to be the people who don't shoot well because of trigger-control issues. If you aren't a good shooter with decent mastery of the basics/fundamentals, then adding a dot sight isn't going to make you any better. As illustrated by the study you linked above, some folks can/will occasionally miss an entire IDPA TARGET, and that almost certainly isn't a sighting problem.
     
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  5. sciolist

    sciolist On the Border

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    My experience with dots on pistols is that they print the same for competent shooters. Everyone doesn't index the same way, but that's a different story. The relationship between dot and hit is the same.
     
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  6. tundracamper

    tundracamper

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    And you are writing an article on this topic?
     
  7. PEC-Memphis

    PEC-Memphis Scottish Member

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    Doh ?
    I'd pretty much agree. different RDS's have different amounts of parallax. Poor centering of the "dot" by the technique of the shooter could change the POI/POA - with some sights more, and other sights less.

    As I recall, some sights claiming to be "parallax free" really weren't.

    From a post I made a few years ago ....

    Many [most ?] people believe that RDS's are [positional] parallax free based on manufacturer's claims/statements. I recently watched a "explanation of parallax" video from a [normally] pretty good [commercial, not just some youtube guy] source, where they stated that RDS's are parallax free. There is good evidence to show that this is not true. This is a fairly old article [with some more current minor updates], but I don't see it referenced very often, so for your reading pleasure:

    Comparative Study of Red Dot Sight Parallax
    https://www.greeneyetactical.com/2017/07/27/comparative-study-of-red-dot-sight-parallax/


    A note about parallax(es):

    When using optical sights, there is a shift of the POA/POI based on the position of the eye relative to the axis of the optic. This is what is discussed in the article.

    The "other" parallax is because it is impossible for the optic (or iron sights) to be co-axial with the bore; ie. the "sight" path is offset (usually vertically) from the bore path. So when performing bullet drop calculations, the height of the optic above the bore path is part of the calculation.
     
  8. DJ Niner

    DJ Niner Staff Member Moderator

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    The bold text is the key. I included something similar in the first line of my answer, above.
     
  9. ChiefWPD

    ChiefWPD

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    Yup. I have eight books out, plus a couple of dozen magazine articles. Keeps me out of the local bars.
     
  10. sciolist

    sciolist On the Border

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    An example of what I'm talking about would be production vs. open.

    I'm a production shooter. I zero my guns so that a 20 yard group is tangent to the top of the post. That means on almost any USPSA target, my gun prints above the post. If I'm shooting fast splits, I need to allow for some vertical delta. But generally, hits are never going to be below the top of the post.

    When I visually engage a plate, my attention comes to its center. But I index the post about 1/3 up from 6:00. That would be true at 8, 15, 20, even 35 yards. So I have a tendency to index a dot in that same manner.

    An open shooter OTOH, probably just looks at the dot as POI. It is always exactly where the hit will be with an appropriate trigger press. And open shooters have a tendency to index irons with the top of the post right at POI... or even with an FO dot at POI - which I never do.

    Even on warp-drive splits, I index the FO below where I want the first hit to be.

    So that it an example of how a production shooter could see an open gun as printing low. Because it was zeroed by someone who puts the dot right where he wants the hit to be. But once the production guy starts indexing that dot at POI, it will print the same as it does for the open shooter.
     
    Last edited: Sep 1, 2018
  11. Schrag4

    Schrag4

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    Yup. A red dot looks like a dot with a tail for me without my glasses on.
     
  12. DJ Niner

    DJ Niner Staff Member Moderator

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    True with the electrically-powered red dots, but if you get a chance, try to find and look through one of the Trijicon dual-illuminated (non-electrical) RMRs. I get NO distortion of the dots on these sights. Some folks with more severe vision problems still get some distortion, but others report a nice round dot.
     
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  13. YakSpitRamp

    YakSpitRamp

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    What an excellent question sir, I never thought about that. I will use the responses here and see what else I can find. My initial thought is a bore laser tool is universal for everyone and everyone sees the same thing (assuming unimpaired fight) so it must but I feel a need to verify that in the field (is what I will tell my wife when she asks why I'm range to the range for the 7th day in a row)
     
  14. NDcent

    NDcent Socially Inept

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    A red dot reflex should be used with glasses on, especially if you wear glasses for reading, and both eyes open. Put the dot on the spot you want to hit, it's that simple. You can move your head around all you want, as long as the dot is on the spot, you're good.

    So, yes if they, you, or me puts the dot on the spot, and the gun was sighted in for that, it should shoot as accurate as the user.
     
  15. TheDuckhunter

    TheDuckhunter

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    Try the 6 MOA Dual-Illuminated RMR. I have no halo/starfish with mine vs the 3.25 MOA RM06. YMMV, but its worth a try.
     
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  16. happie2shoot

    happie2shoot

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    I have zeroed around a thousand sights of
    different kinds since around 1966,
    it is part of what I do for a living and hobby.

    Just changing your grip or position, stance, off bench,
    can change your zero, you have to be good enough of
    a shot and have the range far enough and have a gun
    accurate enough to see the difference.

    Some guns are not precision enough to see a small
    difference in zero.

    As an experiment, hold your gun with a very stiff
    arm and grip and shoot some groups, then hold
    a very weak arm and grip, you will see a difference
    if you can shoot small groups.

    I usually hold very stiff and my guns usually shoot
    high for most other shooters.

    I test loads off the bench but zero for my handguns
    standing, for hunting.

    Zero your gun how you intend to shoot it.

    As far as red dot sights, even if it is fuzzy with a
    tail, if you hold it the same every time, it will still
    group.
     
  17. babue

    babue

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    I have loaned my RMR equipped guns out to 4 new shooters at what would be a beginners handgun class. They were sighted in for me. All the new shooters, if they had a good grip and decent trigger control were able to get A zone hits out to at least 15 yards and shot a passing score on the qualifier. Red dot equipped guns make it easier for a beginning shooter to achieve a good score. They still must develop the ability to use the irons as a backup.
    Everyone is a little different in how they fire a weapon. So there is likely to be a small difference that a dot gun sighted for an individual will shoot to their exact point of aim and maybe slightly off for a second shooter. Overall I think if the gun is properly sighted in any one picking it up who has some experience using that style weapon will get the performance that is desired.
     
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  18. Tomkat

    Tomkat I Like Beer

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    The answer should be "yes" using every sighting system. It varies more with iron/ghost ring/etc type sights than it does with red dots and lasers because red dots and lasers have only one point of reference (no rear and no front sights). Non red dot and non laser sighting is affected so much by alignment that it can vary significantly from shooter to shooter. Even with iron sights, if a subsequent shooter aligned the sights as you did, assuming proper fundamentals, they would hit the same place you did. Note that when you are sighting in your red dot (actually the same for lasers and iron sights) that you are adjusting the sighting mechanism to the point of impact. Thus, assuming no further adjustments either intentionally or accidental, the sighting system will be aligned with the point of impact. Please note that this is assuming, as I said, proper fundamentals and identical hold. If I set mine for a center hold and a subsequent user shoots with a 6 o'clock hold. Subsequent shooter will hit low; but, his bullet will hit exactly where the red dot was aligned.
     
    Last edited: Oct 2, 2018
  19. hmendelson

    hmendelson

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    What I have found with my Trijicon RMR is once it is sighted in, you put the red dot on the target and it will hit the target. The red dot doesn't have to be centered within the rear lenses. Be careful when cleaning the gun, if you get cleaner or oil on the lenses it will take some time to get the stuff off the lense and remove the smears on the lense.

    Sent from my SM-G950U using Tapatalk