12-06-2011, 04:12 PM
You need to know what your actual carbine's muzzle velocity is first, then run the numbers through a free on-line ballistics program. I use Berger's a lot since it's simple.
You need your MV with that load, the BC data of the bullet, your optic height above bore, and your environmental conditions, with temperature being the most important. Run those through a ballistics program, and set the output units for MOA. You will have to multiply your MOA drop data by 4 to get your click values. A lot of programs have those options for you, (to enter in scope turret click values).
Once you have your data, put it into usable click value form, since nobody will be dialing 10.98 MOA, for example. That is 11 MOA, or 44 clicks with a 1/4 MOA scope.
Anyway, most guys have a small card with the range column on the left, their elevation correction for that range next to each range increment, and wind correction at that range for a 10 mph full-value wind. You can tweak your wind data to the conditions since windage is a linear function, not like elevation trajectory.
So you have a little card attached to the stock or hanging from your scope mount that you can reference. You're at a known-distance range, or have lased a target at 400 yds. Let's just say your elevation correction next to 400 yds on your card is "11 MOA" or "44 clicks" on your 1/4 MOA click scope. You will dial your elevation turret 44 clicks, which moves your reticle 11 MOA lower in the FOV if you were able to watch it in a vice. The barrel will now be oriented higher in order to lob the projectile in a path that will intersect the target at 400yds.
If you have a full value wind with wind direction blowing from right to left, your barrel needs to point into the wind to compensate. Let's say the wind is 10mph for simplicity, and your data says you need 3 MOA of windage to compensate for that wind speed at 400yds. You will crank your windage knob so that the reticle moves with the wind, or to the left, which points your barrel more to the right.
Now you take the shot and should be dead on, provided the conditions didn't change. If the wind shifts direction and is now coming from over your right shoulder and blowing to your left over your left shoulder, it is a half value wind, and you cut your windage correction in half down to 1.5 MOA, or 6 clicks with your 1/4 MOA turrets.
That 129gr SST is a big pill to push for a 16" Grendel. I would recommend staying with the 123gr bullets and under, but you'll still be effective for hunting within 200yds I'm guessing.
Now you see why a lot of guys like Mils more and more, since it is all based on 10, with .1 Mil click values, and a Mil reticle to match. You will also find out really quick why a zero-stop is pretty much a must, unless you mark your scope turret with a paint pen to indicate where your zero is.
The fastest method I've found so far is custom BDC decals for your load and turrets:
![[Image: Finland2009latest122.jpg]](http://i1085.photobucket.com/albums/j422/LRRPF52/Finland2009latest122.jpg)
You need your MV with that load, the BC data of the bullet, your optic height above bore, and your environmental conditions, with temperature being the most important. Run those through a ballistics program, and set the output units for MOA. You will have to multiply your MOA drop data by 4 to get your click values. A lot of programs have those options for you, (to enter in scope turret click values).
Once you have your data, put it into usable click value form, since nobody will be dialing 10.98 MOA, for example. That is 11 MOA, or 44 clicks with a 1/4 MOA scope.
Anyway, most guys have a small card with the range column on the left, their elevation correction for that range next to each range increment, and wind correction at that range for a 10 mph full-value wind. You can tweak your wind data to the conditions since windage is a linear function, not like elevation trajectory.
So you have a little card attached to the stock or hanging from your scope mount that you can reference. You're at a known-distance range, or have lased a target at 400 yds. Let's just say your elevation correction next to 400 yds on your card is "11 MOA" or "44 clicks" on your 1/4 MOA click scope. You will dial your elevation turret 44 clicks, which moves your reticle 11 MOA lower in the FOV if you were able to watch it in a vice. The barrel will now be oriented higher in order to lob the projectile in a path that will intersect the target at 400yds.
If you have a full value wind with wind direction blowing from right to left, your barrel needs to point into the wind to compensate. Let's say the wind is 10mph for simplicity, and your data says you need 3 MOA of windage to compensate for that wind speed at 400yds. You will crank your windage knob so that the reticle moves with the wind, or to the left, which points your barrel more to the right.
Now you take the shot and should be dead on, provided the conditions didn't change. If the wind shifts direction and is now coming from over your right shoulder and blowing to your left over your left shoulder, it is a half value wind, and you cut your windage correction in half down to 1.5 MOA, or 6 clicks with your 1/4 MOA turrets.
That 129gr SST is a big pill to push for a 16" Grendel. I would recommend staying with the 123gr bullets and under, but you'll still be effective for hunting within 200yds I'm guessing.
Now you see why a lot of guys like Mils more and more, since it is all based on 10, with .1 Mil click values, and a Mil reticle to match. You will also find out really quick why a zero-stop is pretty much a must, unless you mark your scope turret with a paint pen to indicate where your zero is.
The fastest method I've found so far is custom BDC decals for your load and turrets: