How to Calculate Reticle Substension with Magnification Change

Discussion in 'Scopes, Optics, LRFs, Spotters, BoreScopes' started by Lone Hunter, Apr 13, 2019 at 6:42 PM.

  1. Lone Hunter

    Lone Hunter Silver $$ Contributor

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    Could someone please help me in a way to figure my reticle substensions when I change magnification on my scope??
    My scope is a NF 12x42x56BR. It has 40 MOA total elevation. Reticle is NP1-RR. Scope has dots at 4moa,8 moa, 15 MOA, and 20 MOA. The ranging shows correct for 22x on the scope . My question is how can I figure out (besides shooting it) where the dots would be on say 32x or 42x?? . After a 100 yd zero I have 26.4 MOA left in the scope. Enough to shoot 600yds but not 1000 yds. What I was going to do was use the dots as holdovers but want to increase my magnification past 22x. Attached is a picture of the reticle.
    Any and All help would be greatly appreciated.
     

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  2. dstoenner

    dstoenner Silver $$ Contributor

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    It is just a simple ratio of the reference magnification divided by the in use magnification times the reticle value. So for example you are using a magnification of 32 and you want to see about the 10 moa dot. It is (22/32)*10= 6.875 moa

    HTH

    David
     
  3. Lone Hunter

    Lone Hunter Silver $$ Contributor

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    David,Thank You For the reply. My holdovers or dots are substended at 4,8,15,20 MOA. By your reply all I would have to do for each dot is your formula and that will give me the holdover MOA for the substensions? If I wanted to turn magnification up to 42x then I would use your formula like (22/42)*20=10.48 MOA. That means at 42x the 20 MOA dot Substension would be 10.48 MOA? I hope this is correct!! If so, it is a lot simpler than I thought. If not, what would the 20 MOA dot be? Thank You, Greg
     
  4. John Valencic

    John Valencic

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    Strelok Pro does the calculation for you in his app. After inputting yardage, hit "reticle " and your reticle shows the distance at whatever power is dialed in, and this can be done on the fly.

    Screenshot_20190414-070141_Strelok Pro.jpg
     
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  5. dstoenner

    dstoenner Silver $$ Contributor

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    You are correct and you are welcome

    David
     
  6. Lone Hunter

    Lone Hunter Silver $$ Contributor

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    John, I have Strelok Pro and like it. The problem is as most scopes are calibrated at one magnification. My 5.5x22 and 12x42 are both calibrated at 22 power. That's where Strelok calibrates at 22x. That was why I was asking about different magnifications. MOA Dot is different at different magnifications. Look at Strelok and see but I believe they only go to the ranging power which is 22x. I like also how you can dial it in with he turret on top top. Thanks, Greg
     
  7. Lone Hunter

    Lone Hunter Silver $$ Contributor

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    David, Thank You Very Much For The Help. I Really Appreciate It. Very simple way to figure things. Greg
     
  8. Zero333

    Zero333 Silver $$ Contributor

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    No matter what the calculation, you still should verify with live ammo at 100 yards. Sometimes when the scope is at 30 power it might actually be at a true 27 power.


    At 42 power you would multiply the holdover values by 1.9090909090909 = (42/22)

    So at 42 power....

    4 moa dot = 7.636363636363 moa = ( 4x1.90909090909)

    8 moa dot = 15.272727272727 moa " "

    15 moa dot = 28.636363636363 moa " "

    20 moa dot = 38.181818181818 moa " "
    ------------------------------------------------------
    36 power = 36 /div by 22 = 1.6363636363636

    4 moa dot = 4 x 1.63636363636 = 6.5454545454544 moa

    etc.................
     
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  9. Rem06

    Rem06 Silver $$ Contributor

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    or get a FFP and clear your cranium up some?
     
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  10. Lone Hunter

    Lone Hunter Silver $$ Contributor

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    Too much money invested to do that. Hell, if it’s easy it wouldn’t be any fun .. LOL
     
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