Measure sight height for ballistic calculator with 20 Moa base?

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xopher

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I just purchased the shooter iPhone app yesterday. While inputting my rifle info, I noticed there's a section on sight height. Now here's the problem, my scope is mounted on rifle using one of those 20 Moa bases which are slightly canted.

Where would you more experienced guys recommend making the measurement?
 
I've noticed from playing with the ballistic calculator, that sight height certainly does have an influence on the perceived ballistics, but it isn't so sensitive that .020 to .060 of an inch is going to mean anything. A 20moa base tilts the scope approx 20 thousandths of an inch higher at one end of the base compared to the other. I would just measure from the centre of the scope tube and ignore the tiny discrepency, if any.
 
I'm pertty sure you use the bore center to the objective lens (front element) center.

Canting your scope is done to increase the available range of adjustment. This small shift in optical center line will then be dialed out as you zero the scope. So the cant of the scope rail should not really affect the measurement. Thus I use the point where the light first enters the optics as the point of referance.
 
Grizzlypeg said:
I've noticed from playing with the ballistic calculator, that sight height certainly does have an influence on the perceived ballistics, but it isn't so sensitive that .020 to .060 of an inch is going to mean anything. A 20moa base tilts the scope approx 20 thousandths of an inch higher at one end of the base compared to the other. I would just measure from the centre of the scope tube and ignore the tiny discrepency, if any.
Click to expand...

From the center of the scope to the center of the barrel, or the top of the barrel ?
 
Thanks guy

Ill give this a try next weekend and see if the estimates are a little closer.

i noticed inputting atmospheric conditions also off sets it by 10 clicks haha (
 
Grizzlypeg said:
Centre to centre, otherwise the irrelevant thickness of the barrel would affect the calculations.
Click to expand...
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Roger thanks ... i havent had to much difficulty in side 1000 so i never really used that input. However as i reach out i know its gonna matter. Glad someone brought this up. No one where im from is really shooting past 600.

... Self taught on denile and error ;)
 
pilot2001 said:
Roger thanks ... i havent had to much difficulty in side 1000 so i never really used that input. However as i reach out i know its gonna matter. Glad someone brought this up. No one where im from is really shooting past 600.
Click to expand...

It won't matter. The farther you go, the less the location of your sights matters. At extremely close distances (25 yards, 15 yards, or less), the effects are much bigger (MOA-wise).
 
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