Bullet drop with Elevation change

Discussion in 'Long Range Hunting & Shooting' started by Niceshot, Aug 20, 2019.


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  1. Niceshot

    Niceshot Member

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    Got a newbie question for you guys. Got a 300 wm that is a tack driver and have been shooting here in the PNW at 1100' elevation. Headed to Wy in October and the elevation back there will be in that 4500-5500' range. How much POI change can I expect with this elevation change? Is there a rule of thumb for this? I got the tools (RF) that will make this correlation for me but just looking for some insight prior to our trip.
     
  2. Rick Richard

    Rick Richard Well-Known Member

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    If you know your load data and velocity, then you can go to any ballistic calculator input the info and then it will give you the results you are seeking. I do this all the time using the Berger Ballistics Calculator. Good luck!
     
  3. Niceshot

    Niceshot Member

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    Thank you Sir! That was about as easy as it gets.
     
  4. cohunt

    cohunt Well-Known Member

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    If you can, check your mv and zero when you get to your hunting area ...often times they will change a bit
     
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  5. Quicksilver338

    Quicksilver338 Well-Known Member

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    While always a good practice before any hunt, a ballistics calculator should compensate for this based on your zero location and conditions compared to your current location and conditions.
     
  6. cohunt

    cohunt Well-Known Member

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    "Should" doesnt always work at long distances, that's why it's best to check and confirm.
     
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  7. For going from country to country and elevation to elevation applied ballistics app and an AB kestrel are on it. Now I have the kestrel 5700 that pairs with the phone and it’s awesome. Also have a rivanov Eagle and that’s the best. It calculates any cant in your rifle and any angle and gives you your elevation hold as well as wind hold (or what to dial). Pared with a laser it’s amazing.
     
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  8. Quicksilver338

    Quicksilver338 Well-Known Member

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    Elevation won’t change your zero enough to notice. Other stuff happens, which is why I agree with you to always double check your zero after traveling. To go from a zero at sea level to 10,000ft and 24” of barometric pressure and your zero shifts by .02”. Yes this is based on the ballistic calculator and 100yd zero. But at that distance not much changes, downrange everything is magnified as this equates a 8” change of vertical drop at 500 yards from an average 6.5 creedmoor, but that’s from the elevation and lower pressure more so than the .02” zero shift. I doubt anybody here is good enough to shoot that .02” change in their zero nor their rifles capable of it. It’s best to be trained to use your calculator correctly and to practice and know your abilities in different situations downrange.
     
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  9. catamountsierra

    catamountsierra Well-Known Member

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    While you ballistics app of choice should be able to account for it, as long as you have the needed input data, I think it is good to understand what is causing the changes that you end up seeing. Most of the time, going up in elevation puts you in thinner, drier air, which creates less drag on the bullet. Less drag means that your bullet retains velocity better, which means that it takes less time to get to the target and has less time for gravity to act on it; less time under gravity means that it doesn't fall as far below line of sight and effectively impacts higher. If you don't account for the differences, you will tend to shoot high at altitude.
     
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  10. waveslayer

    waveslayer Well-Known Member

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    Send me your data and I can run the info for you. With any temperature change, humidity and elevation you will get a POI because thinner the air less resistance on the bullet, less drop you get...

    No general rule of thumb because of so many variables. BC has a lot to do with it.

    Download Hornady 4DOF or AB ballistics app or a personal favorite TRASOL to give you all the data. Do you have a Bluetooth Kestrel? If not, get one
     
  11. Yep. Get an applied ballistics kestrel and all your questions will be answered on the app. I’m sure all the dudes here will be happy to help you set it up if you need. I prefer AB, Todd is always at the front of ballistics and an all around awesome person. DT uses trasol so I’m sure it’s awesome too. But I don’t think you’ll find the same library of ammo as AB.
     
  12. waveslayer

    waveslayer Well-Known Member

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    I had a lot of issues with the AB Kestrel and it is overly priced!
    Bluetooth Kestrel= $200
    BALLISTICS APP= $10-$30, or free
    =$230 bucks at most.
    Ballistics Kestrel = $600-$750

    It's nice all in one, but I develop a DOPE card and only need a range so I'm just as fast if not faster using my DOPE card. Buy a Sidewinder Industries DOPE card holder and you will be sold while hunting

    The TRASOL has gotten me first round hits at a mile. It runs a good ballistics engine
     
  13. Bravo 4

    Bravo 4 Well-Known Member

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    Less time of flight also means less wind deflection as well...plus more energy carried further.
     
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  14. Recon$$

    Recon$$ Well-Known Member

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    The kestrel is overpriced IMO but it's the best thing out there I think. I don't think you need one if your shooting 400-500 yards max. If your shooting longer distances I find it's well worth it. You can see changes of .3/4 Mil at a 1000 easily in a day with varying weather. When the first shot counts, it's worth it.
     
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