Questions about my drop chart

Usually around that 600 yard range will be where you start seeing things start to go of the rails if your not quite right.

You gotta nail your enviromentals first, you then need to give your calculator good data, shooting chrony's will leave your some room for tweeking so make sure everything else is nailed. Scope hight, range to target, BC, turret value, then you can concentrate one basically zero and velocity.
It's easiest to verify your zero is solid by shooting at 300 on paper, if your zero is of a little it'll show because velocity or BC isn't really visible yet so I tune my zero hight to match what it should be.
Then put up paper at, 300, 600 and 1000 and I dial and shoot these fast one round at each as close to the same condition as possible.
Measure it up and tune your velocity, I can usually get a solid tune to 1500 yards inside 20 rounds with this method.
 
bigngreen said:
Usually around that 600 yard range will be where you start seeing things start to go of the rails if your not quite right.

You gotta nail your enviromentals first, you then need to give your calculator good data, shooting chrony's will leave your some room for tweeking so make sure everything else is nailed. Scope hight, range to target, BC, turret value, then you can concentrate one basically zero and velocity.
It's easiest to verify your zero is solid by shooting at 300 on paper, if your zero is of a little it'll show because velocity or BC isn't really visible yet so I tune my zero hight to match what it should be.
Then put up paper at, 300, 600 and 1000 and I dial and shoot these fast one round at each as close to the same condition as possible.
Measure it up and tune your velocity, I can usually get a solid tune to 1500 yards inside 20 rounds with this method.
Click to expand...
This makes a lot of sense to me. I'm gonna go this route. I'll report back as soon as I get some results. Thanks bigngreen!
 
Given your shooting form, tall test(scope), environmental inputs, cosine(slope) adjustments, etc are understood/corrected,, I would first, confirm your initial results with another test. If your results are similar to your first test, I would do a velocity calibration. The Shooting Chrony's I have used were consistently off by as much as 70FPS, usually low Compared to my Magnetopeed and Lab Radar. The easiest way to make the adjustment would be to increase/decrease the velocity in 20FPS increments in your ballistic calculator until the outputs match your actual drops at the various ranges. Correcting for velocity, and/or BC is a fairly common exercise, even when chronographed velocities are accurate. The particular rifle/barrel can induce differences. Since your drops are falling off at 500 yards, I'd adjust velocity. When drops start changing further out (+700 yards), tuning BC may be necessary. IMO.
 
I'm going through my notes on all my range sessions. I feel a neccessary test will soon be to find a flat place to shoot 800-1000. I dont have a range to shoot at, so I've been hiking in the mountains to shoot (a lot of work). I think I'll go east of town to the flats next. I want to eliminate the cosine factor. Me being new to this I think getting rid of a more experienced shooters game might help.
 
DIDIHITIT? said:
I went out again and shot 800, 650, and 550. I have found that to 500 my drop chart is dead on. At 550 I'm shooting a half moa higher than my chart says. The same goes with 650. 800 is nearly 1.5 moa off. The spot I'm shooting is uphill. Maybe a 15 degree angle. But at 650 I was almost level with target and still hit high. I brought it down and put them right in the center. Have you guys had this same experience. I dont wanna change everything and skip a step. This conclusion is drawn after 60 rounds and 2 different shooting sessions. View attachment 180143
Click to expand...
As stated earlier it's garbage in garbage out first off make sure all your bullet information is correct and precise use a G7 BC also I run Shooter ballistics because I can run multiple BC's a lot of apps only take one average and then as far as trueing your data which must be done at greater distances you will see as the velocity drops your BC goes up this may be your problem if you have a chronograph you know your correct speed at the muzzle the app will adjust to speed at different distances but you must use the correct BC for that distance which is why I run multiple BC's this photo is from Bryan Litz his book ballistic performance of rifle bullets 3'rd edition compare it to the data on your bullet make sure everything is correct
8D2694E0-5F05-43C8-8CB8-E2471A06D13B.jpeg
 
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