15 moa bases

Discussion in 'Long Range Scopes and Other Optics' started by snowpro440, Jun 4, 2009.

  1. snowpro440

    snowpro440 Well-Known Member

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    Does anyone know if there is a website that will calculate bullet trajectory if I put a 15 MOA base on my gun. Or will I have to shoot it to see how many clicks for every 100 yds. I shoot a 308 with 168s at 2800 fps. Zero is at 100 - want to be able to shoot 800 yds. 5 MOA will get me to 400 yds and this doesn't match the standard ballistic calculator. any help would be appreciated.:cool:
     
  2. AJ Peacock

    AJ Peacock Well-Known Member

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    Which scope do you use?

    Have you verified that each click on your scope moves the point of impact the correct amount? It's easy to do. Shoot a group at 100yds, then move your scope 10MOA up and shoot another group. The group centers should be about 10.5" apart.

    Tell us more about your load, exactly which bullet you are shooting and it's velocity (assuming you've chronographed it with at least one good chronograph).

    Also, which ballistic software are you using.

    Where are you shooting, ie. what is the elevation/barometric pressure?

    Also, how far off are the ballistic calculations in comparison to your actual drops?

    How much up elevation adjustment does your scope currently have left from your 100yd zero?

    AJ
     

  3. AJ Peacock

    AJ Peacock Well-Known Member

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    Using exbal and the 168gr Berger VLD's and 2800fps. With a 100yd zero, it should be 7MOA to get to 400yds. Either your velocity is incorrect, your scope is not moving the correct amount for it's click value or it's shooter error.

    AJ
     
  4. snowpro440

    snowpro440 Well-Known Member

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    ok here goes i am shooting 30" barrel 308 ftr say 1400 elevation with average 65 temp actual 2820 fps with 168 hornady match 100 yard zero weaver t 36 scope 8 clicks to 1 moa , I move 9 clicks for 200yds 28 clicks for 300 an 42 clicks for 400 . my scope is 1.9 inches center of crosshair to center of bore .It just doesnt make sense , i dont have access to shoot 800 yet but i wanted a good idea where i would be at or if i can get to 800 with the scope? Most others that shoot 308 ftr with a different scope ,still 1/8 clicks turn more clicks than me but i figured that was because of my bases still dont configure on a bal.listic chart
     
  5. AJ Peacock

    AJ Peacock Well-Known Member

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    The only thing that makes sense is that your scope clicks are not 1/8 MOA. Perform the test that I listed to verify your scope moves as expected. The base won't make any difference on your drops. The only thing a base will do, is to enable a greater elevation change.

    AJ
     
  6. Leupold308

    Leupold308 Active Member

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    hard to argue with the math, seems to me scope could be the problem, tapered bases would not be the problem.
     
  7. CAM

    CAM Well-Known Member

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    Snowpro440
    all good info so far.
    The 15MOA base will not effect the bullet drop!
    It will only move the crosshair higher in the scope at 100 yards, giving you 15MOA more scope adjustment.

    Cam
     
  8. snowpro440

    snowpro440 Well-Known Member

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    yea i cant figure this one out , I thought that the angle of the scope vs bullet path would change some of the clicks but this is getting too crazy to figure . So it must be the scope because when i shoot the groundhog shoots.thats what i click to get on target everytimelightbulb
     
  9. AJ Peacock

    AJ Peacock Well-Known Member

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    What scope are you using?

    AJ
     
  10. snowpro440

    snowpro440 Well-Known Member

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    weaver T36