scope correction factor

Randy dawson

Member
Joined
Feb 14, 2018
Messages
23
Location
Texas panhandle
If you have a scope correction factor of say 4% how do you adjust a ballistic calculator to take this in account? I have an idea but was wondering how other people did it. Do you change the bc or velocity to match the 4%? I don't know what mine is exactly yet but I know its some. Please don't tell me I need a new scope. I just need to figure the right formula for the one I have. thanks
 

coyotemaster

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Joined
May 7, 2004
Messages
110
Location
Kewanee il
4% is quite a bit imo. I'd think you could fudge the B.C. Number a bit and be close. Bryan Litz addresses this error in his video explaining the tall target test.
 

coyotemaster

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May 7, 2004
Messages
110
Location
Kewanee il
Ok I would shoot at 300 400 500 if you have the space and juggle B.C. and/or velocity to stay close to adjusted elevation.Is this scope repeatable?
 

Blancoalex

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Joined
Jul 28, 2019
Messages
447
Location
Texas
Think your talking about turret click value. Your scope is adjusting either only 96% or 104% per click. You should have place in your app to make this adjustment.

96%(.96 moa/mil) acutal movement would need you adjust your app to correct to 104%
104%(1.04moa/mil) acutal movement would need you adjust your app to correct to 96%

My Shooter app correction is adjusted in the firearm setup under Elevation Correction Factor or Wind Correction Factor.

This only appiles if you have 100% proven your scope has this error.

It is good you discovered this as the error adds up the further out you go.

Hope this helps.
 

jebel

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Joined
Jun 15, 2018
Messages
341
Location
Oregon
Think your talking about turret click value. Your scope is adjusting either only 96% or 104% per click. You should have place in your app to make this adjustment.

96%(.96 moa/mil) acutal movement would need you adjust your app to correct to 104%
104%(1.04moa/mil) acutal movement would need you adjust your app to correct to 96%

My Shooter app correction is adjusted in the firearm setup under Elevation Correction Factor or Wind Correction Factor.

This. I use both Applied Ballistics Mobile (ABMobile) and Ballistic AE. They both also allow you to correct for the true turret click value.
 

Canadian Bushman

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Joined
Jan 24, 2012
Messages
1,814
Location
Houston, Texas
4% sounds like a lot.

If you are determining correction factor with live fire chances are it will not be correct.

This needs to be done with the scope mounted firmly, optically centered, and aimed at properly scaled ruler or grid standing plumb and square at a very precise distance. I usually do it as close as i can and have the scope be parallax free.

Out of the handful of scopes ive tested for tracking errors, most resulted in a correction factor that was essentially lost in the size of my groups. Most were something like .997 or .998 for correction values.
 
Last edited:

Canadian Bushman

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Jan 24, 2012
Messages
1,814
Location
Houston, Texas
C67D225A-7879-4FC6-AB0C-A8C7211859F6.png

Shooter App

EF4E6389-F0A7-4CBB-A85D-E9F0FE728B32.png

AB App
 

badthirtyone

Well-Known Member
Joined
Nov 26, 2007
Messages
448
Location
Denver Colorado
4% sounds like a lot.

If you are determining correction factor with live fire chances are it will not be correct.

This needs to be done with the scope mounted firmly, optically centered, and aimed a properly scaled ruler or grid standing plumb and square at a very precise distance. I usually do it as close as i can and have the scope can be parallax free.

Out of the handful of scopes ive tested for tracking errors, most resulted in a correction factor that was essentially lost in the size of my groups. Most were something like .997 or .998 for correction values.
Great response.
 

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