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Stupid diopter question

Discussion in 'Shooting Gear and Storage' started by Dunkelheit, Apr 5, 2013.

  1. Dunkelheit

    Dunkelheit Well-Known Member

    Maybe a stupid question, but how do i correctly use a diopter sight? I never used one before. I shot a Springfield 1922 in .22lr today at 50yrds distance. The groups were nice and tight but all far to high above. The slight on the right side with the scale showed 50yards. I think the sight was a lyman model 48.
  2. Edarnold

    Edarnold Well-Known Member

    Lieber Herr Dunkelheit: first question is where the front sight was aligned on the target. For target shooting the standard alignment is the round black center of the target centered in the diopter aperture, sitting on top of the front sight blade. If you are aiming at the center of the target, your shots will of course go high.

    If you have the sights so aligned, the knob on the top of the rear sight may be used to adjust the point of impact. Look at the scale on the right side of the sight, you will need to turn the knob to lower the aperture, which lowers your point of impact. You may need a lot of clicks, each click you feel when turning the knob should lower the point of impact by 1/8" at 50 yards.

    I hope this information enlightens your darkness

  3. Dunkelheit

    Dunkelheit Well-Known Member

    Dear Edarnold,

    i had the target sitting on the front blade, but maybe i didnt center the target in the aperture correctly. At the end i had to change the height on the scale to zero yards to hit close to the center.
    If i understand correctly i have to turn the knob on the top many clicks to change the point of impact. Do i have to turn it clockwise to get the point of impact down or reverse?
    Has the front sight blades top to be in the center of the aperture like in a ghost ring shotgun sight?

    Thank you
  4. rcmodel

    rcmodel Member in memoriam

    Yes, centered.

    But don't try to focus on the rear sight aperture.

    Concentrate on the front sight blade and let your eye find the exact center of the hole in the rear sight.

    Your eye will automatically find the center of a hole when you look through it, not at it.

  5. Dunkelheit

    Dunkelheit Well-Known Member

    I tried it again today, scale at zero yards, knob on the top as far as possible, different shooters and still 2" to high. Maybe a to small aperture? I dont have a idea what to do now. Im thinking about getting rid of it.
  6. rcmodel

    rcmodel Member in memoriam

    Aperture size has nothing to do with zero.

    It will shoot to the same zero if you drill it out to 1/8".

    What you need is a taller front sight.

    But regardless of that.

    It doesn't sound that far off.

    Target shooters use a 6:00 o'clock hold with the bullseye resting on top of the front sight blade.



  7. Dunkelheit

    Dunkelheit Well-Known Member

    Thats what i did. If i aim in the incorrect "too low" postion its close to the bullseye.

    You are absolutely right, i need a higher front sight because i cant get lower with the rear sight.

    So may it be usual that i dont hit the bullseye with the 50 yards adjustment at 50 yards distance?

    Is it possible that the original issued sights are useless at 50 yards or did the military never shoot less than 100 yards during the training?
  8. rcmodel

    rcmodel Member in memoriam

    The Springfield 1922 was not intended to be a 'training' rifle in the sence they were used a long range on outdoor hi-power rifle ranges..

    Col. Brophy referred to them as "gallery practice rifles."

    They were most often used at reduced 25-50 yard range, or even indoor shooting in National Guard armory's and such when high-power rifle ranges were not available.

    For whatever reason your rifles front sight is too low.
    Perhaps someone changed it over the last 90 years and used the wrong replacement sight?

  9. Edarnold

    Edarnold Well-Known Member

    If I remember correctly, clockwise will lower the aperture and so
    lower your point of impact. Don't have a Lyman 48 sight handy so I'm going by memory. If you got the scale on the side down to zero, you went the right way. The scale on the side of the sight can't be depended on to indicate the range, really it just gets you back to a previous setting for a particular range. Only shooting the rifle and adjusting the sights will get you the correct setting for a particular and the way you are holding the rifle, the ammunition you are using, etc.

    Is the front sight a thin blade that is pinned into a band around the barrel? That would be the original style sight; if the front sight is something different than that, then the sight was changed at some time and that might be why it's shooting so high. Also, the original purpose of the rifle was shooting on indoor 50 foot ranges, which is where I used one of these rifles in High school ROTC. At close distances the difference between the line through the sights and and the bore of the rifle means you actually need more elevation than at longer distances. That might be a factor as well.

    And if you just get tired of the rifle, contact me. They are fine guns that I have fond memories of, I'd be glad to buy it from you and give it a good home.
  10. Dunkelheit

    Dunkelheit Well-Known Member

    Edarnold you saved me the day. I took the rifle out to range this morning and followed you advice. I ignored all markings and adjusted it again. I tried different ammunition and i finally got it close to where i want it, even with the 6 o clock hold.

    Next to the elevation knob there is a small screw which prevents the diopter slide from touching the receiver. Im not sure if its for adjustment or something else but i turned it out a bit and got the 0.08 inch i needed. I took a picture of the sights, maybe you can tell me if it is the correct one or not.
    If not, is it true that is it the same front blade as used in 1903s? I know there are different height blades avaible for it.

    Also thanks to rcmodel for the good advice.

    Attached Files:

  11. rcmodel

    rcmodel Member in memoriam

    Once sighted in, you screw that screw down against the receiver and it becomes a depth stop.

    Then the sight slide can be removed from the sight base for cleaning under it, or taken off and stored separately to prevent damage to the sight.

    And then returned to the exact same elevation setting when you put it back on the rifle.

  12. Edarnold

    Edarnold Well-Known Member

    That is the original style front sight, as you found there are different heights available. Since you have your vertical zero under control, I doubt if you'll need to change the original. As rcmodel said, the screw alongside the adjusting knob is to to give you a fixed height to return to if you remove the sight staff. The knurled knob on the front of the sight base is a spring loaded takedown mechanism, in case the staff needs to be removed. You turn it counterclockwise several turns to loosen it, then push in to release the staff. Since you have your sight about set up I would NOT remove the staff! From your target, it looks like you need a little left windage to center your groups and you will be in business. Same deal for windage adjustment, use the knob on the left side of the sight staff to move the aperture to the left.

    By the way, nice group!

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