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Thanks form..finally got a few mil scopes from swfa this sale instead of my usual MOA and will be referencing this post. All of Form’s post holds true for ffp MOA scopes as well. Only difference is you would set adjustments to be .25 and swap it to moa And if you did that you'd be wrong. You've just illustrated why Mils is superior to MOA. A Mil is always a Mil, but 1" is not the same as 1 MOA. Just like 0.25" is not 1/4 MOA . 0.261" is 1/4 MOA. (one MOA = 1.047") It may not seem like much, but when you shoot long range small errors compound. . Correct me if I am wrong but I don't see anywhere where MallardAddcit said anything about inches at all. Just like one click on a MILs scope is always .1 mils regardless of distance. One click on a MOA scope is always .25 MOA. Both MOA and MILs work fine....so long as you just leave any sort of linear measurements out of it. I agree that tenths are easier to work with in my mind than fractions but neither really is that big of an issue.
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BTW great post Form the pics really helps with the explanation. Already sent this post to several friends to better help them understand what all them lines on the reticle mean and how to use them.  Great follow up info as well Jordan! I agree this thread needs to be a sticky!
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Gents,
Another great post, always appreciate it when those who know their schitt share their knowledge & experience in a non-inflated manner. Form and Jordan are two of the best at it.
Bob
Enjoy life now -- it has an expiration date.
~Molɔ̀ːn Labé Skýla~
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Campfire Kahuna
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Campfire Kahuna
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Thank you for the information gentlemen.
_______________________________________________________
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LOL
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When you needs some tips on applying Thread Lock let me know I'm sure I can get ya up to snuff
My dog is a member of the "Turd Like Clan"
Covert Trail Cameras are JUNK
3 Time Dinkathon Champion #DinkGOAT
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Absolute pressure refers to whether you're entering the actual air pressure compared to a vacuum, or if you're entering air pressure corrected for sea level. If you're located a few thousand feet above sea level, and you see a reading of 29.92 InHg, then you're reading relative, gauge, or barometric pressure. If you look at your Kestrel and see a reading of 25.62 InHg, then you're reading absolute pressure. Absolute pressure read off of a handheld device is preferred, as it bypasses conversions and local weather station input. FYI, if you have an iPhone 6 or newer, your phone has an air pressure gauge built in, and you just have to get the "Barometer" app to get absolute pressure readings from your phone without having to use a Kestrel or similar.
Enable Zero Atmosphere means that your app will compare your current shooting atmospheric conditions with the conditions present when you zero'd the scope with that load, and will calculate the difference in your zero for use in your current shot solution. If this is clicked off, the app just leaves your zero the same for any atmospheric condition.
I use Ballistic:AE instead of Shooter, so I'm not 100% sure, but I'm guessing that MV variation is a measure of the temp sensitivity of the powder you used in your load, and how much the MV changes for each degree F in temperature change.
Jordan, have you been able to get Ballistic AE to use the iPhone internal barometer and gps for measurements instead of looking for data from a local weather station? I thought it was supposed to per the literature, but with cell and wifi turned off to test it, it fails to populate any weather data on my iPhone 6s. I only just downloaded Ballistic AE a few days ago though so I may be missing something. I know the sensors on my phone work fine because Strelok does use the internal barometer and GPS, although I don't like the app layout as much. As a side note, a handy iOS app I discovered recently is Density Altitude+; it's a very simple app that calculates density altitude from the device sensors and a temp input, which defaults to a local weather station but can be manually adjusted too. Well worth the $1.99 for the app.
Last edited by Yondering; 12/08/17.
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If you had posted this before black friday they would have sold 3x as many of them...
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Campfire Outfitter
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Absolute pressure refers to whether you're entering the actual air pressure compared to a vacuum, or if you're entering air pressure corrected for sea level. If you're located a few thousand feet above sea level, and you see a reading of 29.92 InHg, then you're reading relative, gauge, or barometric pressure. If you look at your Kestrel and see a reading of 25.62 InHg, then you're reading absolute pressure. Absolute pressure read off of a handheld device is preferred, as it bypasses conversions and local weather station input. FYI, if you have an iPhone 6 or newer, your phone has an air pressure gauge built in, and you just have to get the "Barometer" app to get absolute pressure readings from your phone without having to use a Kestrel or similar.
Enable Zero Atmosphere means that your app will compare your current shooting atmospheric conditions with the conditions present when you zero'd the scope with that load, and will calculate the difference in your zero for use in your current shot solution. If this is clicked off, the app just leaves your zero the same for any atmospheric condition.
I use Ballistic:AE instead of Shooter, so I'm not 100% sure, but I'm guessing that MV variation is a measure of the temp sensitivity of the powder you used in your load, and how much the MV changes for each degree F in temperature change.
Jordan, have you been able to get Ballistic AE to use the iPhone internal barometer and gps for measurements instead of looking for data from a local weather station? I thought it was supposed to per the literature, but with cell and wifi turned off to test it, it fails to populate any weather data on my iPhone 6s. I only just downloaded Ballistic AE a few days ago though so I may be missing something. I know the sensors on my phone work fine because Strelok does use the internal barometer and GPS, although I don't like the app layout as much. As a side note, a handy iOS app I discovered recently is Density Altitude+; it's a very simple app that calculates density altitude from the device sensors and a temp input, which defaults to a local weather station but can be manually adjusted too. Well worth the $1.99 for the app. Thanks for the tip on the Density Altitude app, I'll check it out. The GPS doesn't get used to populate weather data, IME, but the barometer does get used to populate the absolute pressure box. Sometimes you have to click the "get weather" button, then click on the pressure box specifically for the measured pressure data to appear. I thought it was just a glitch that sometimes happens with my particular phone, but it might be more broad-based than that.
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Campfire Ranger
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Gents,
Another great post, always appreciate it when those who know their schitt share their knowledge & experience in a non-inflated manner. Form and Jordan are two of the best at it. +1
Screw you! I'm voting for Trump again!
Ecc 10:2
The heart of the wise inclines to the right, but that of a fool to the 24HCF.
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Big fan of that set up. Wish I'd gone MQ instead of MD on mine.
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Campfire Ranger
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Campfire Ranger
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And on a side note, I'd love to see that reticle in a 6x42 Leupold body and forget the turret.
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Thanks for the thread!
2 questions:
1) In the walk-through, Shooter back-calculated to an MV of 2860, but in the next picture, MV was listed as 2840. Why is that? A calculation issue? I'm not familiar with shooter.
2) Why in the world did someone come up with 'density-altitude' rather than just using station pressure and RH? What's the advantage?
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Campfire Outfitter
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Campfire Outfitter
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There are only two things that affect bullet flight; air and gravity. Gravity is simple but air is very complicated. Air density- the medium we are shooting through- is dependent on temperature, pressure, altitude, humidity... you get the point.
Density Altitude is the real air pressure we are dealing with based on true altitude combined with temperature etc to give a more accurate representation of the density of the air the bullet is dealing with. Better data results in better solutions.
Cold air is dense, hot air is thin.
NRA Benefactor Member
Those who live by the sword get shot by those who don't.
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I've heard high air is thin, and low air is thick..... The lowlanders that come up here elk hunting swear by it.....
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Get a pilot's license & "density altitude" will make a lot of sense!
"The more I am around people the better I like my dog." Mark Twain
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Campfire Member
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Excellent information in this thread.
Thanks.
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Campfire Member
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Is the free app istrelok any good or should we just pay the $10 for shoooter app?
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Campfire Tracker
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The free strelok is really hamstrung, the $10 Version works great. Shooter is good as well. I use both at whim
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2) Why in the world did someone come up with 'density-altitude' rather than just using station pressure and RH? What's the advantage?
as dennisinaz said, it's a way to simplify things; instead of using 3-4 different weather value inputs, you can use just one. FWIW temp plays a big part in this calculation even if the elevation doesn't change; for example in my area near sea level, we're at -1,500 to -2,000 ft density altitude right now (clear and cold weather), but it will change to 2,000+ ft d/a when it warms up a bit and gets cloudy, even without climbing the mountains. Taking that a step further, you can print a dope chart for every 2,000 ft change in density altitude in your area and have your bases covered pretty well all year round.
Last edited by Yondering; 12/09/17.
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