Getting Your Inputs Squared Away Part: 1
Why multiple parts? You’re going to have to buy some things in all likelihood and it’s best if I give you a week in between editions to make purchases and get them set up with the rest of your gear and learn how to use them and all that jazz.
First thing’s first: Garbage In, Garbage out. I’m not kidding. If you skimp on your data you’ll cut your maximum effective range in half or worse. Little things make a huge difference when the distances grow. You’re going to need to burn some ammo and you’re going to need to burn some more cash. You’re going to have to spend at least a pair of days at the 100yrd bench doing velocity logging. You’re going to have to spend a little time in the field testing your kit and making sure you’re able to make those shots.
To begin with you need a Kestrel weather meter. There might be other brands but quality matters and Kestrels are quality. You need temperature and barometric pressure and wind. There are Kestrel models that also provide ballistics data and humidity data, etc… Get the one that fits your budget. Here’s a quick chart to help you decide. You need temperature. You need wind. You need barometric pressure. If your working range exceeds 1000m then you probably should have humidity too.
Once you get your Kestrel start off by reading the manual and setting the elevation to zero so that you always get an absolute barometric pressure reading. This will make Ballistic_XLR and all other ballistics calculators treat you a lot better.
Now take that Kestrel outside and screw around a bit. Notice the difference between how wind moves across the ground compared to how it moves a few feet and several feet above the ground. See how being at the foot of a hill and the peak of a hill and in the trough of a valley affect your wind readings.
Now you have to come to terms with the fact that reading wind is an art and predicting the wind value correction you have to make for a really long range shot is something you learn to do with greater and greater precision by getting out and doing it.
I use a Kestrel 3500. It doesn’t do humidity but humidity doesn’t really matter enough to be that worried about. I have to adjust up a click or down a click if it’s desert conditions or almost raining respectively. So what I do is add a half click to my elevation and take the extra click if my solution lands at .03MRAD or more above an even number. So if my firing solution minus humidity says 10.33MRAD and I’m in the desert with ultra low humidity and I add that half a click I get 10.38 (10.33 + .05). If my firing solution says 10.31MRAD then adding the half click gets me 10.36 and I do not take the extra click. This is sort of like rounding except that my trigger number to round to the next click is 80% instead of 50%. The .03MRAD of slop that’s in there can be held or dialed or ignored depending on the range.
What about other brands? Sorry man. I found that in this case there are other instruments that are of the same quality but they’re of the same price too and since Kestrel have been adopted by the community it’s probably best if you blend. Then when you need one you can borrow it and know instantly how it works.
We’ll come back soon with Part 2.