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  #22  
Unread 04-06-2013, 03:39 PM
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Join Date: Feb 2012
Location: South Louisiana
Posts: 30
Re: Need Help

Would I be correct if I were checking to see if my scope is tracking vertical I would shoot a shot at 100 yards add 27MOA shoot at 100 yards again, would that show if the bullet was tracking off vertical?
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  •   #23  
    Unread 04-06-2013, 04:48 PM
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    Join Date: Jan 2013
    Location: Meridian, Idaho
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    Re: Need Help

    You could for sure. You could do a box test as well.
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      #24  
    Unread 04-06-2013, 05:34 PM
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    Join Date: Feb 2012
    Location: South Louisiana
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    Re: Need Help

    Ok great I saw that on TV once.
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      #25  
    Unread 04-07-2013, 06:42 PM
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    Join Date: Oct 2012
    Location: Colorado
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    Re: Need Help

    Quote:
    Originally Posted by lougonl View Post
    Would I be correct if I were checking to see if my scope is tracking vertical I would shoot a shot at 100 yards add 27MOA shoot at 100 yards again, would that show if the bullet was tracking off vertical?
    This should work really well. You should also be able to verify if the scope is tracking perfectly verticle as well (use a level to make sure that the vertical change is plumb). If your scope is not level, this would help show it.
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      #26  
    Unread 04-07-2013, 07:59 PM
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    Join Date: May 2008
    Location: South of Canada and North of Wyoming
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    Re: Need Help

    Quote:
    Originally Posted by lougonl View Post
    I have 2 long range rifles but will talk about one today. I am having problems with my ballistic solution I cannot get it to match up. I have shot my data and know what MOA is needed to hit zero and several distances but cannot get the balistic programs to match up with this data and I have tried a few programs. I will list the data I have if someone can please tell me what I am doing wrong, I am desperate. I am faily new at this.
    308 WIN
    168 Grain Berger Classic Hunter
    BC G-1 .496 G7 .254
    Muzzle Velocity 2553 FPS
    Sight above bore 2"
    Sighted in at 200 yards
    Elevation 100'
    Temp 65 degree's
    Humidity 65%
    400 5.5 MOA
    500 8.75 MOA
    600 14 MOA
    700 20 MOA
    800 27 MOA
    Please help me!!!
    I don't see where you mention Barometric Pressure? That will make a difference.

    Things to check...
    -Correct vertical alignment of your scope to your bore, I use a plum bob
    -Actual scope tracking, you can check this by locking your rifle into a rifle vice at a range and checking the travel against a yard stick @ exactly 100 yds from the scope. 120 clicks (30 MOA) should equal 31.41"
    -Accurate scope height.

    Off the top of my head, the cause appears to be either a tracking problem or an incorrect BC or a combination of things. Your rate of ballistic decay is greater than the BC you're using suggesting the actual BC is lower. Velocity is always suspect.

    In this case your actual drops vs charted drops are less @ 400 and 500, about the same @ 600 and lower @ 700 and 800.

    This suggests to me that actual velocity is higher and actual BC lower than programmed.... assuming actual scope height, alignment, and tracking are correct.

    Also need to know the Barometric Pressure.
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    Last edited by MontanaRifleman; 04-07-2013 at 09:55 PM.
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      #27  
    Unread 04-07-2013, 09:45 PM
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    Join Date: Feb 2013
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    Re: Need Help

    Lougonl,

    Hope you are still hanging in there. I thought I would throw this up for you.

    308 Drop Adjustment.pdf

    This ballistics profile matches the majority of your drop MOAs but doesn't quite make much sense. There appears to be an error or multiple errors in your actual drop MOA correction or you have a variety of ranging errors needing confirmation. Here is a list of steps I take to help isolate ranging errors.

    1. Confirm the range. Should be pretty easy if shooting on a range with known distances or verified with a rangefinder. I don't see this as being the problem
    2. Apply muzzle velocity variation to the ballistics solution. Again, it will be helpful if you can confirm your velocities with a chronograph and provide your calculated ES and SD.
    3. Confirm atmospheric conditions. Has your air density changed?
    4. Confirm elevation turret correction settings. Is your scope tracking correctly and have you confirmed click values and verified your zero? Have you applied the corrected solution to your elevation turret? (The later will not apply in your situation with developing actual drop comparisons).
    5. Is your ballistics solution validated? Have you used two sources to validate your ballistics solution? The solution above is not validated.

    Hope this helps and take one bite at a time. Good luck and good shooting.
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      #28  
    Unread 04-08-2013, 05:11 AM
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    Join Date: Feb 2012
    Location: South Louisiana
    Posts: 30
    Re: Need Help

    Oh yea still hanging in there MMERSS.
    I am starting my 7 days off tomorrow I will take these tip one at a time and start rulling things out. I want to thank everyone for the help. I will let you know how I come out.
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