Adjusting scope for different distances

[alfred1222]

Hey all,
Since we do a lot of leg jumping over the newest and coolest rifles, I wanted to learn a bit more about adjustment of ones dope out at various distances.

Let's say a .308 rifle is zerod at 100yrds, and then the target is pushed back to 200yrds. No wind value. How many clicks, on an MOA scope, would one turn to adjust for that? Is there a chart with this kind of stuff? Or a way to learn to do it better? I shoot pretty decent whenever I get to the 500yard ranges, but that's a lot of guess and check work to account for the wind and range. I want to learn to do it better.

[bsumoba]

If you can't run chronograph numbers and get the BC for your bullet to input into JBM (see link below), then the only way to do it is to go to that yardage and fire a shot, make an adjustment off your shot, then shoot a confirmation shot.

http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi

Otherwise, get your speed at the muzzle or some fixed distance, get your bullet BC and input the variables into JBM and you will get a close approximation of your elevation adjustment.

For wind, the ballistic apps will give a good approximation as well.

[tanks]

There is an app for that . I use "Snipe" that is on my iPad/iPhone. I have a ballistic reticle so do not worry about clicks. I know what the dope is for every dot and -. However, if I wished I could do the clicks as the software has that as well.

Of course, I also verify at the range. Snipe has been accurate to 600 yards (my max testing).

[E92335i]

Yup there's an app for that. I use MD Ballistics on my iPhone. Input your rifle data, ammo, wind, elevation, etc....

[hj_S14]

get an Kestrel with AB

[Fjold]

You have to know the exact information about your loads and ambient conditions and then build a drop chart to match that.

Bullet, velocity, altitude, humidity, wind, etc.

[NiteQwill]

To add, the Vortex Long Range ballistic chart is also a handy tool:

http://apps.vortexoptics.com/lrbc/

Just plug in your numbers. It automates the weather and atmospheric changes.

[Arnelcheeze]

another app to use, Strelok, if your lucky your reticle is included. A chrono or ballistic info would be needed also...

[JMP]

get an Kestrel with AB

This is what I do. But, the data out depends on good data in. However, the 308 Win is such a common cartridge with not that much range, if you stick with a given rifle and ammo, you'll pretty much remember all your values at baseline conditions, which are where you often shoot.

For the first few hundred yards most rifle cartridges have similar drop and then the divergence grows rapidly between two given loads.

I haven't shot in MOA for a while, but I'd guess in round numbers it's probably about. That'll get you reasonable close with just about any 308 so you can spot and adjust from there. It's pretty easy to shoot as long as you practice.
100-0
200-0.5
300-3
400-6.5
500-10.25

[hj_S14]

To correct my post, JMP actually advised me to get the Kestrel.
BTW.. I would listen to this guy , he knows his stuffs . A warning though, he doesn't eff around with his gears so it can be super expensive but buy once cry once

This is what I do. But, the data out depends on good data in. However, the 308 Win is such a common cartridge with not that much range, if you stick with a given rifle and ammo, you'll pretty much remember all your values at baseline conditions, which are where you often shoot.

For the first few hundred yards most rifle cartridges have similar drop and then the divergence grows rapidly between two given loads.

I haven't shot in MOA for a while, but I'd guess in round numbers it's probably about. That'll get you reasonable close with just about any 308 so you can spot and adjust from there. It's pretty easy to shoot as long as you practice.
100-0
200-0.5
300-3
400-6.5
500-10.25

[iroquois]

Applied ballistics solver

You can access the Applied Ballistics solver here.

http://appliedballisticsllc.com/ballistics/

This version also provides the weapon employment zone analysis.

[windrunner]

Hey all,
Since we do a lot of leg jumping over the newest and coolest rifles, I wanted to learn a bit more about adjustment of ones dope out at various distances.

Let's say a .308 rifle is zerod at 100yrds, and then the target is pushed back to 200yrds. No wind value. How many clicks, on an MOA scope, would one turn to adjust for that? Is there a chart with this kind of stuff? Or a way to learn to do it better? I shoot pretty decent whenever I get to the 500yard ranges, but that's a lot of guess and check work to account for the wind and range. I want to learn to do it better.

You have to go out and shoot your desired distances. If you are being consistent with the rounds you are using, the data you gather will provide consistent results. If you truly want accurate data on what your rifle/scope/ammo combination provides, that is the work you have to put in.

[huckberry668]

Strelok is what I use on my phone. It's free and mobile at the range. Get a cheaper wind meter if you really want to figure out the wind.

These are some easy steps I'd recommend for long range shooting on the cheap. You can save $ on the unnecessarily expensive equipment (chrono, wind meter etc) for a good scope.

1. download a ballistic app like Strelok on your phone.
2. Shoot 1 group at 100 yards and 1 group at 200 or 300 yards with the same POA and measure the drop difference between groups' centers.
3. Plug in your bullet's weight, ballistic coefficient and varying velocities into the calculator till you get the same drop value. Now you have your velocity and ballistic table (in MILs) for the ammo.
4. You can crank the turret without buying a new scope or buy a MIL scope, utilize 'hold over' method with your ballistic table. You won't need to crank your turret at all. I write the values down and stick it to the lense cap so i can see while in shooting position.

you can even do this at home using online calculators. my favorite is JBM. It gives you a list of bullets to choose from without needing to know the ballistic coefficient.

[ar15barrels]

Hey all,
Since we do a lot of leg jumping over the newest and coolest rifles, I wanted to learn a bit more about adjustment of ones dope out at various distances.

Let's say a .308 rifle is zerod at 100yrds, and then the target is pushed back to 200yrds. No wind value. How many clicks, on an MOA scope, would one turn to adjust for that? Is there a chart with this kind of stuff? Or a way to learn to do it better? I shoot pretty decent whenever I get to the 500yard ranges, but that's a lot of guess and check work to account for the wind and range. I want to learn to do it better.

Read these:

http://www.caprc.com/forums/viewtopic.php?f=28&t=36

http://www.caprc.com/forums/viewtopic.php?f=28&t=37

[Rwnielsen]

That was very informative reading, thanks.