Originally Posted by kappa8
This may not measure up to LR standards, but asking here anyway. Out to 500-600 yards, what do you use for chronograph? Muzzle data is easy to collect, and Labradar will measure out to 100 yards. But what do you use downrange? Setup a secondary chrono? Would like to understand the bullet speed downrange as well as muzzle.

For 500-600 yards.
Let's take the cheapest chrono out there.
Or for that matter, factory ammo with a published MV on the box.
Let's say your load is consistently around 1/2" at 100 yards off the bench. It's not your best group, but it's not worst-An Average.
Have a solid 100 yard zero, and slip your dials/zero your turrets out
With a free online ballistic calculator, put in your MV (Cheap chrono or Published MV).
Put in the BC (Don't care if it is G1 or G7-Whatever is published for the bullet).
Give the approximate elevation and temp, and throw in 50% humidity (or leave it alone).
Get your parallax set for 300 yards.
If you don't know how to do this and how to focus your ocular check out some YouTube videos
Dial up for the distance-4.25 MOA is what your cheat sheet says, and on paper or steel fire three shots at 300 yards.
Pay attention to where they group vertically compared to your aiming point (Have a specific aiming point).
Let's say the center of your three shots is a 1/2 MOA low (1.5" approx). Dial up a 1/2 minute - 4.75 MOA, and shoot one shot at 3 again.
Let's pretend it is spot on.
Write all of it down.
Look at your computer generated dope sheet for 400, and it says 7 MOA. Since you were a 1/2 MOA low at 300, add a half MOA, just for giggles, and dial up to 7.5 MOA. Shoot three shots, and find where the center is from your aiming point.
Again adjust if needed and fire a shot and document.
Go to 400 yards and do the same thing.
Check your parallax as you move further out. also check to keep your rifle level. A working scope level is a good thing too.
Rinse and repeat...Write it all down.

You are just walking it out and documenting it.
You actually don't even need a chrono or ballistic software-Nothing wrong with having them (I have them!).
You are developing an actual hardened drop chart for that day and atmospheric conditions.
Even if your clicks are consistently less or more, it doesn't matter, as you are finding the drops it takes for your rife, scope, and load at those distances...
Rinse and repeat on another day.
Try to find days where the wind is calm and mirage is not high.

Ernie "The Un-Tactical"

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