Getting on target right away

[flims]

I have lately taken up the interest again to see how accurate chairgun could work out the wind drift ballistics for my .25, 31grain H&N barracuda. Now i know that the elevation numbers are usually close but i decided to take some more time at this then i did before.

I already have my comeups done at the range from anywhere from 15yards to 131 yards. these have been tried time after time and they work. i inputed my 917ft.s and all the other info and then checked the environmental conditions and entered them as my kestrel showed. i then checked the drop chart chairgun showed with the numbers i had. these where very close with the biggest variance being that of about .5mils which even at longer distances means 2-5inches off, however it was only the 125m come up that did not match as close to the others, so i either ranged it incorrectly or i have to check it again. i had to increase the velocity on Chairgun slowly up to 10ft/s more to get everything matching.

I then checked the windage chart which i had to convert to Mile/hour while i used meters for distance. i have been practicing to read wind in mile/hour so i decided to keep with the same units altough it can be done in m/s. the program gives you a reading for 5, 10, 15 mile/hour etc..
since airguns and rimfires tend to be easily susceptible to wind even a change in 1mph(at long range) i decided to divide all the values by 10 so as to get the drift for 1mile/ hour.

At the range: This is the hardest part of all. so this is what i use and it seems to work very well. when im at the range before i take a shot, i'll open up my wind meter to have an idea of what the wind is doing at my position. slowly you can also tell what the wind is doing however most of the time you will say it is roughly between 3-5mph and then read the wind for 4mph. the meter helps you gauge this more accurately and then i look around me and start noticing what different things are doing around me, meaning if the small leaves are vibrating slowly or the flowers are moving steadily left to right, try to look at what similar objects are doing from 1/2 to 2/3 of the range to the target. it is important to notice how long does a condition last. Remember the wind closest to your position will move the Point of Impact the most since it opens up the angle so if the wind in the first 50meters is realy prominent, focus and correct for that.

if i think the wind is 3-5mph, and it keeps gusting to 6mph, i will also work out how much off will that wind drift that pellet so if a 3mph drifts it 1mil at 100 and 6 drifts it 1.5mils then dial for 1mil and if it gusts constantly hold off 0.5 mils.

when working out the calculation i like to use this. decide where the wind is coming from ex 10 oclock or 9 or 11.30, then the value of this according to the wind clock and the velocity of the wind. so in your mind you should say
'its a left to right wind from 11 o clock, 1/2 value at 5mph. look in your wind data sheet, see the 1mile/hour value for that wind multiply by 5 then half this value eg. 0.1milx5=0.5/2= 0.25mils. Always dial into the wind so in this case we dial 0.2mils left. with some practice even an after noon one, you can get use to the procedure. that doesn't mean you always get first round hits because that depends on your wind estimation not the formula. the formula outputs what you input. Junk in junk out.

i have managed to place constant hits within a 2" circle. remember once you dial the correction focus on the reticle on target and your trigger pull. make sure rifle is not canted and squeeze gently. Watch for the impact and record the point of impact on a note book. i'm hoping to have a small video clip of this procedure. you can train for this even if you are not at the range. carry your weather meter and when you feel like guess a wind condition and then open your meter to confirm. you can get realy good at this. Caution don't do this when in the presence of the missus or she will start feeling that a gust of wind and a little fan are taking her place and forget your gust)

here is something i was working on to help me get the figures together without having to check various papers and tables for numbers. this way i just turn the window to the range and i get the Elev in Mils, the wind for 1,5,7mph. i could include other stuff but this is enough most of the time. i still need to laminate it. there is a british company that makes these professionally. The have some of the most popular factory loads or else you can give them your load and they will have one done for you. remember this is for a particular weather condition so you will have changes from summer to winter. home made stuff is fun. will give it a spin this weekend.
http://pic18.picturetrail.com/VOL888.../316583743.jpg

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