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Old 24th March 2011, 06:50 PM
PeteM PeteM is offline
Senior Member
Join Date: Nov 2008
Location: Chagford, Dartmoor, Devon
Posts: 446
Smile Angle Corrected Range - Up/Down Shooting

I have now conducted some testing on this subject:
(Angle Corrected Range - Up/Down Shooting)

My findings thus far are as follows:
  1. up or down to an angle of 15 no compensation or very little is required.
  2. up or down to an angle of 20 approx. shot goes 5mm high
  3. up or down to an angle of 25 shot goes 8mm high
  4. up or down to angle of 30 shot goes 11mm high
  5. up or down to an angle of 35 shot goes 15mm high

A simple formula is used to work out the Angle Corrected Range
Cosine(Degree of Angle) * Measured Range = Angle Corrected Range

* = multiplied by

I set up at a horizontal distance of 25 yards with an ASLI (Angle Slope Level Indicator) device
manufactured by Horus Vision LLC, USA. (manual attached). This device has a scale with the degree of angle on one side & the cosine of the angle opposite it.

So the ranges were:
  1. 0 = 25 yards
  2. 15 = 24.14yards
  3. 20 = 23.49yards
  4. 25 = 22.65yards
  5. 30 = 21.65yards
  6. 35 = 20.47yards

I have attached an Excel calculator. This is a work in progress.
I am writing the code for a web based app that I will eventually include on the Calculators Page of the SWEFTA Website

The shot always goes high, only after 15, then by increments.

From my experience very few Field Targets are set at an angle of more than 25 & I would say the average is between 5 to 20.

I believe (from what I have read about this subject) that as the distance increases from the target the amount that the shot goes high by, increases.
At the moment this hearsay for me, as I have yet to test this out on the range.

Well I hope this is of interest, it has certainly been so for me.
Attached Files
File Type: pdf manual_asli.pdf (406.5 KB, 38 views)
File Type: xls UP:DOWN Calculator.xls (9.0 KB, 58 views)
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