May 14, 2017, 02:26 PM | #1 |
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Elevation clicks
I have a very specific situation, I need to know the scope vertical adjustment (in number of clicks) for a upcoming match.
I will be shooting a .308 rifle with a Nightforce scope on it. I have the zero stop set at 100 yards. Cartridge, .308 with 168 gr. HPBT @ 2700 fps. I can only shoot out to 300 yards at my local range. Anybody know how many clicks up to 400, 500, and 600 yards. If you can get me in the ballpark, it would be greatly appreciated. JD |
May 14, 2017, 02:45 PM | #2 |
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Need a little more info on the scope.
Mil or moa adjustments? 1/10 mil per click? 1/4 moa per click? What is the Scope height above the bore?
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May 14, 2017, 04:00 PM | #3 |
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You can always use the "Shoot it and see where it lands" approach.
Using a reliable chart for trajectory and a drop table for your specific ammunition, see what the clicks on your scope accomplish at the 100, 200, and 300 yard ranges you have. And extrapolate from there for the longer ranges. Not exactly the fancy, technical approach, but it can work.
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May 14, 2017, 04:42 PM | #4 |
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You will need the velocity, either by using a chronograph or by extrapolation. Then plug data into a free online ballistic software program and print out a table.
To extrapolate without a chrono shoot dead on at 100. Then at 300. Measure your bullet drop in MOA at 300. Using your program, plug in different muzzle velocities until they match the drop in MOA at 300. That will give you a good idea of your muzzle velocity. Then, like I said above, plug in your data such as velocity, BC, bullet wieght, weather, etc. and print out a table You can download a free app on your phone (Strelok works quite well) and then use it prior to shooting your match. You can enter and save your velocity, BC, and local weather and generate a table right there. |
May 14, 2017, 06:45 PM | #5 |
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Very rough: For a similarly-performing handload, zeroed at 200 yards, I had to come up 32 clicks (8 inches at 100 yards) to hit near center at 500 yards.
I've found that the tables in the appendices of the Sierra Reloading Handbook to be extremely helpful in predicting trajectories. |
May 14, 2017, 07:51 PM | #6 |
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From my days shooting an M1A
for service rifle matches, I recall that the required elevation adjustment for that bullet at that velocity is 3 minutes of angle per 100 yards. Thus from 300 to 400 is 3 moa up, then another 3 moa from 400 to 500, then another 3 moa from 500 to 600.
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May 14, 2017, 08:20 PM | #7 |
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May 15, 2017, 10:25 AM | #8 |
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I don't have all the data but this should get you in the right area
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May 15, 2017, 12:48 PM | #9 |
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Thanks
Thanks for the input.
I've got enough here to get me on the paper now. That's all I need , then I can fine tune as the match progresses. |
May 15, 2017, 01:28 PM | #10 |
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Don't forget to take copious notes so you won't have to use any more matches as practice sessions.
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May 16, 2017, 06:34 AM | #11 |
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Everyone I know has an Android device (phone, tablet) of some type...
Download "Strelok" from the Play Store. Even with chrono data, "close" is sometimes what you get, sometimes spot on. Either way, an actual match is a lousy place to develop dope. Hopefully you can find a place to practice at longer ranges. Wind is just beginning to be a major factor around 600 yards (and is certainly a minor one even at less) and if you're unable to shoot at those longer ranges at which you're competing you'll be unable to develop the skills needed to dope it- and you'll be unable to compete effectively. It isn't "dial, point and shoot" at that range and further out.
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May 17, 2017, 12:06 AM | #12 |
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Nice table, but I have to ask, how does one get a .9 CLICK?
(or point anything click?) I can get 3 clicks, I can get 4 clicks, but I'm totally in the dark how to get 3.9 clicks.
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May 18, 2017, 10:41 PM | #13 | |
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Quote:
Oh, yeah. I forgot. Men never read the instructions! If you substitute .065 for the gravitational pull of the moon, add 3.14 for the burger you ate before the match, and subtract just about enough for how far you are from the equator in millimeters, you can get it!
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May 19, 2017, 10:20 AM | #14 |
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don't be silly, 3.14 isn't the factor for a burger, its the factor for pie!
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All else being equal (and it almost never is) bigger bullets tend to work better. |
May 19, 2017, 02:23 PM | #15 |
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GOOD ONE!!!!!!!!!
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May 19, 2017, 05:57 PM | #16 |
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Find out how many clicks your scope was built with. I have never shot 600 yards, possible it may need different bases. Probably not at 600, but I dunno.
One half assed way to do it, would be to see how many clicks up you can turn your gun, that is zeroed at 100 yards, see how high on target it goes. Should tell you if you have enough range in your scope. Do a balistics calculator, to se the path it should have. This would be the first thing I would do. |
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