Bullet Drop

Discussion in 'The Basics, Starting Out' started by 700, Jul 9, 2003.

  1. 700

    700 Well-Known Member

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    faw67

    I am not familiar with this software system.

    Charts are usually plotted with respect to where the crosshairs are zeroed.

    Regards

    700
     
  2. faw67

    faw67 Member

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    Oct 5, 2002
    Ok guys Im sure this is a simple ?
    I have some software for a palm pilot called ballistic, now when Im figuring hold over do i use the bullet drop from muzzle or from the scope, I personally think it is from the scope but there has been some discussion here , just want to make sure that i am using the right numbers before i make a chart up to put on the scope
    Thanks FAW
     

  3. Brent

    Brent Well-Known Member

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    The software should ask you for a specific zeroed range, this is the reference point it will go by to give you another zero point out farther. Your scope height above the bore line should be another input it asks for too.

    Good luck. [​IMG]
     
  4. Brent

    Brent Well-Known Member

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    Faw67,

    was is hold over figured from drop from barrel or the scope?

    You're going to have to give me an example of what your thinking, I'm not really understanding what "your" understanding of drop and compensating for it is just yet.

    It's pretty simple, but how do you understand it and how to compensate for it at this point.... just so we're on the same page and save us some time here.

    There is apparent drop, and actual drop.

    Apparent drop is relative to your line of site(LOS) and zero range, actual drop is relative to the bore line only. [​IMG]

    just want to make sure that i am using the right numbers before i make a chart up to put on the scope

    What numbers are you worried about using and where are you getting them from in the first place? You just need to give a better idea of what you're doing and what you understand concerning this to get to the bottom of it for you. [​IMG]
     
  5. faw67

    faw67 Member

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    Hey thanks for the help , i got a copy of point blank yesterday and the numbers run close to the others i got but here is a clip of what im lookin at :
    Name: .223 Cal, nosler btbt, 55 grn
    Ballistic Coeff: 0.267
    Bullet Weight: 55
    Velocity: 3000
    Target Distance: 100
    Scope Height: 1.850
    Temperature: 70
    Altitude: 500
    Range Elevation Velocity Drop Max Y
    0 yds -1.85 in 3000 fps 0.00 in -1.85
    25 yds -0.99 in 2913 fps 0.12 in -0.71
    50 yds -0.38 in 2828 fps 0.50 in -0.61
    75 yds -0.04 in 2745 fps 1.15 in -0.44
    100 yds -0.00 in 2663 fps 2.10 in -0.19
    125 yds -0.26 in 2583 fps 3.34 in 0.14
    150 yds -0.84 in 2504 fps 4.91 in 0.57
    175 yds -1.76 in 2426 fps 6.82 in 1.10
    200 yds -3.05 in 2350 fps 9.10 in 1.74

    Im thinkin that i should be using the elevation numbers for holdover bein they are from the scope location
    thanks
    FAW

    [ 07-11-2003: Message edited by: faw67 ]
     
  6. faw67

    faw67 Member

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    yep both of them are in the software just my? was is hold over figured from drop from barrel or the scope?
    i say scope
    FAW
     
  7. Brent

    Brent Well-Known Member

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    With your numbers there, the elevation coulumn is what you are interested in while moving from one zero range to another, dialing in the MOA correction or holding over either one.

    If moving to a 200 yard target or zero, from a 100 yard zero, the bullet will drop below the LOS or point of aim (POA) 3.05" at 200 yards if scope is left zeroed at 100yds. Thus, you need to dial in 1.5 MOA (6 clicks on a 1/4 MOA per click turret) to compensate for the "additional" bullet drop.

    The rifle, if zeroed correctly at 100 yards, will already have 2.0 MOA dialed in to it compensate for the first 2.1" of bullet drop over that distance. Another 1.75 MOA would also be already dialed in to compensate for the scope height above the bore, for a total of 3.75 MOA to get you up on the bull at 100 yards. The turret would be rezeroed and not really indicate this 3.75 MOA up elevation, but it has been compensated for in some way initially.

    At the 100 yard zero point the bullet is at the top of its trajectory, so anything farther will see more bullet drop yet.

    At 200 yards, the 3" of additional bullet drop can be compensated for by divided it by 1/100th the distance from the shooter to the target to determine the correction in MOA needed to rezero at that range.

    For example; 3" at 200 yards = (3/2 = 1.5 MOA)

    24" at 435 yards = (24/4.35 = 5.52 MOA)

    Likewise, if you know it takes 14 MOA to zero at 700 yards, 14*7 = the total drop you were compensating for... 98"

    This is the simple version. [​IMG] This assumes 1 MOA is 1" and not 1.047" it really is, when you get way out there you may need to figure that into the equasion, or if your scope proves to be calibrated for yet something else too... [​IMG]

    Hope that helps some, sorry if I repeated stuff you already knew. [​IMG] [​IMG]
     
  8. faw67

    faw67 Member

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    Thanks, where im gunna be huntin with this gun I will likely be using a hold over instead of dialing in each target , so I wanted to make a little chart to put on the side of the gun with estimated range and amount to aim high at that range. Im get to go out so irregularly, I know I will forget.
    I also get MOA on the figures i get from the other software that is on the Palm , here is a link to the page I got this from and its free http://www.freewarepalm.com/calculator/ballistics!.shtml
    thanks again FAW