i need ballistics help

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by rem700man, Mar 14, 2013.

  1. rem700man

    rem700man Member

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    hey everyone, im in the process of ironing out a future rebuild of my r700 243 bdl into a .308 for lrh and ive just realized i screwed up big time in the ballistics dept. i have a leupold vx3 3.5-10x50 scope that has 57 moa elev & wind. and im trying to decide what scope base to get. i just ran some #s over jbm and came up with some results that i would like you guys to double check for me if you would.

    bullet-208 amax [.648 g1 bc] @2700 fps
    zero @ 100yds
    sight height 1.5" [im not sure what to put into jbm for this]
    max range 1500 yds
    temp -10 f
    pressure corrected box checked
    std. atmosphere @altitude box checked
    alt. 1312 ft asl
    this is what i come up with
    100-0.0
    200-2.3
    300-4.9
    400-7.8
    500-10.9
    600-14.3
    700-18.0
    800-22.0
    900-26.4
    1000-31.1
    1100-36.3
    1200-42.0
    1300-48.3
    1400-55.1
    1500-62.6

    this is where i messed up, i was under the impression that i had all 57 moa of elev after i zerod the rifle leaving me with roughly 55-56 moa of elev. but, from what ive read i would have half of that elev up [i.e 28 moa up and 28 moa down] if i were to go with a 20 moa base i would run out of elev at 1300 yds. is this right or wrong? im all sorts of confused right now lol. thanks in advance
     
  2. MontanaRifleman

    MontanaRifleman Well-Known Member

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    When you zero you loose a couple of MOA. With a 20 MOA base you "should" end up with about 45 MOA of up. You could also try to shim a little.
     

  3. rem700man

    rem700man Member

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    thanks for clearing up my confusion, i gave it a little thought and decided to go with a 20 moa base and have the scopes reticle changed to mil-dot,after i run out of elev. i can use holdovers. im not gonna let something silly like a scope stop me from takin the 208 amax as far as i possibly can:D. thanks again
     
  4. MontanaRifleman

    MontanaRifleman Well-Known Member

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    BTW the G7 for the 208 AMAX is .324
     
  5. Red hunter

    Red hunter Well-Known Member

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    I would like to know a little more on getting 2700fps with a 208gr Amax out of a 308win? I was thinking the 2400 range.
     
  6. MontanaRifleman

    MontanaRifleman Well-Known Member

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  7. Red hunter

    Red hunter Well-Known Member

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    Ok, There is alot there that my brain is not grasping. Not calling it BS by no means. It's that Iam not knowledgeable enough of pressures and bullet design. I have not read a Hornady reload manual either. The things that I have to ask are 1. What barrel lenght and twist? 2. Is this listed in the load manual? 3.40 gr bullet weight increase and only 1 gr less powder? And good grief 300win mag velocities out of a 308 with no damage.
     
  8. MontanaRifleman

    MontanaRifleman Well-Known Member

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    A 300 WM should be able to push a 208 AMAX to 2900-3000 fps with a good slow powder.

    With RL17 i can push 180 E-Tips @ 3200 fps and 210 Bergers @ 2935

    You wont find a lot load manuals with RL17 loads.

    On the other specs, you can ask the OP of the thread.
     
  9. Beng

    Beng Well-Known Member

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    If you are getting a reticule for measuring angles, then make sure its moa and not mrad, when your turrets are moa.
     
  10. deathwobble

    deathwobble Well-Known Member

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    Jul 16, 2012
    might be able to get 2500fps or so with 208s. 2700fps or so with 180s both will be really hot loads. i would also recommend a tree style reticule like a horus or vortex ebr2-b or XLR