12x - multi-sample ranging

[Scotchmo]

Scott Allen wrote an article on ranging, Standard Deviation, and how it affects the hit probability.
http://ftpodcast.com/range-and-wind-uncertainty/


Notice that if you are already ranging with an Standard Deviation of +/-1yd, improving the ranging won't do much to increase the probability of a hit.

What if the ranging SD is +/-5yds? What if you could cut that SD by 30-40%. That results in a big improvement in the hit rate. It can be done, but it takes more time, more work, and more mental effort.

Averaging multiple samples of the same measurement, all with the same SD, results in a lower SD. I think the relationship is this:

n=number of samples
SD ratio=1/(sqrt(n)

n=1, SD ratio=1.0
n=2, SD ratio=0.707
n=3, SD ratio=0.58
n=4, SD ratio=0.50
n=8, SD ratio=0.35
n=16, SD ratio=0.25

It does take more time, so averaging 16 separate measurements is not practical. But averaging of 2 or 3 measurements are possible even when working under a timer. When using a 12x scope to focus range a far target, there are determinable benefits.

The above assumes that your sidewheel is marked accurately. That will take significant time. That's where you can use more than 2 or 3 samples. That preparations happens before a match.

I decided to stick with 12x for all my FT shooting, not just in Hunter and PFT. After thinking about this a lot, I plan on spending more time on my sidewheel markings. That will improve my ranging alternatives when a target does not have a "bracket worthy" feature.