Applied Ballistics Mobile App - Sight Offset not changing any numbers.

[_Raining]

I was playing around with the sight offset numbers and going from 0 inches to 10 inches had zero effect on the elevation/windage. I would expect it to have some impact on windage.

I had thought the math would be something like:
10 in offset while leaving it as 10 inch offset at 100 yards would gives you 10 in offset till infinity.
But if you zeroed it at 100 yards then at 200 you would be 10 inches off, 20 in at 300, 30 in at 400 etc. But I wasn't sure if this was correct so I went to AB app to see what it said the values were. (The idea was, how much offset does it take to become something to concern yourself with).

JBM has numbers change for sight offset but they don't give you the numbers for actually zeroing it up at 100 yards (Instead of the expected 0 elevation, 0 windage @ 100 yards, it shows 0 elevation, 9.5 MOA windage).
H4DOF and Ballistics AE don't have sight offset as an option.

I understand that practically, any offset induced by canting the rifle to fit the shooter then installing the scope level is going to be negligible. This was just for science.

 

[Snuby642]

I think "sight height" above bore and sight offset are two different things.

 

[_Raining]

I think "sight height" above bore and sight offset are two different things.

Correct. Sight offset is going to come from an offset mount, or if you cant the rifle then you are reducing sight height above bore and increasing sight offset (SOH, CAH, TOA and all that magic maths).

 

[Snuby642]

Got ya, I misunderstood.

There is a good thread on here somewhere discussing cant and how some guys set up that way.

I am not good at the math it would take.
I suppose the offset would be in degrees to make it work for that?

 

[Snuby642]

Is the distance in offset measured with scope retical level and the distance measured center to center of bore that way?

 

[_Raining]

Is the distance in offset measured with scope retical level and the distance measured center to center of bore that way?

So if both the rifle and scope are level, there is 0 sight offset and the sight height is center of bore to center of scope. But let us say some dude finds a 45 degree rifle cant comfortable. We cant the rifle 45 degrees then relevel the scope to gravity. Let us assume a scope height over bore of 2". Then your scope height is Cos(45) * 2 = 1.4" and your scope offset is sin(45) * 2 = 1.4" (45 degrees makes an isosceles triangle).

 

[_Windrider_]

Simply put, the scope offset is measured from center of bore to center of optic.
This number only matters if you also have a zero offset. If you are able to zero your scope with no zero offset then it doesn’t matter if the scope is over the bore or not. But if you have a zero offset of .5” and a scope offset of 1”, AB can account for this in the solutions.

 

[_Raining]

Simply put, the scope offset is measured from center of bore to center of optic.
This number only matters if you also have a zero offset. If you are able to zero your scope with no zero offset then it doesn’t matter if the scope is over the bore or not. But if you have a zero offset of .5” and a scope offset of 1”, AB can account for this in the solutions.

I tried giving AB a zero offset of 2" and the data for a sight offset of 10 inches and 0 inches are the same.

 

[_Windrider_]

I tried giving AB a zero offset of 2" and the data for a sight offset of 10 inches and 0 inches are the same.

Well maybe I’m wrong or missing something. Let’s see if @DocUSMCRetired sees this and chimes in.