Last trip to the range...

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by AtownBcat, Jun 3, 2010.

  1. AtownBcat

    AtownBcat Well-Known Member

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    I am still a novice shooter...so maybe only medium roasting.
    I have developed a load of 73.5g H4831, 180g accubond, RWS Brass, BR2 Primer (300WM)
    I had two chronos with me. A Beta master that recorded(average of 10 shots) 3145fps
    The second was my new CED M2 that measured(same 10 shots) 3059fps.
    I plugged the 3059fps into my ballistic fte(iphone) and shot these four shots at 500 yards.(see pic below)i only shot these 4 because i was running out of time.
    As you can see I'm at least 2 3/4 inches high and as much as 4 3/4. My problem is im having a hard time wrapping my head around Mil-Rads. I have a NXS with mil/mil. If I plug the 3145 into the FTE program it calls for 18 clicks instead of 20. Would this put me where I need to be? Does this mean the Beta Chrony was closer to the actuall FPS? I wish I would have never heard that .1 mil = roughly .33 inches at 100 yards.
    [​IMG]
     
  2. ICANHITHIMMAN

    ICANHITHIMMAN Well-Known Member

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    Faster bullet = less MILs you have to come up that seams correct. As for which chrono is correct I dont know.

    As for the group at 500 yards it is very nice. Im not sure about the Ballistics program as I dont own one or a nightforce scope. It may be that your scope is not tracking 100%.

    Are you sure all the data you inputed to the iphone was 100%?

    Jon
     

  3. tackb

    tackb Well-Known Member

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    easy ,come down 2 clicks and shoot another group and from that you will be able to work out your 500yd zero , WRITE IT DOWN, then continue to do the same for other distances untill you have a data book with everything you need to get hits at distance. It don't really matter what your scope adjusts in as long as YOU know how many clicks you need for a given distance ? this kind off data is what makes first round hit's happen.

    great group by the way !
     
  4. AtownBcat

    AtownBcat Well-Known Member

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    Thanks for the kind words on the group(not sure that 4 rounds count as a group though...)

    I wish I would have had more time that day I would have done that.

    I believe that all the info is input into the iphone correctly but I will check and make sure.

    I had heard that the program was pretty spot on so I was hopeing that it would be, but I guess gathering the data for myself is a safer path.
     
  5. tackb

    tackb Well-Known Member

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    I use ballistic fte on my i phone and its fab , extremely accurate for me but there really is no substitute for actually shooting the distances.

    once you get your actuall data you can then cross reference it and adjust the velocity etc on your i phone to get a perfect match?
     
  6. X3MHunter

    X3MHunter Well-Known Member

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    Jul 8, 2009
    Ok, looks like the center of your group is 3.6" high at 500 yards [(2.6" + 4.6") / 2 = 3.6"]

    A mil is 3.6" at 100 yards, therefore it is 18" at 500 yards (3.6" x 5 = 18"), then you divide that by 10 to get the value of each of your .1 MILS, so 18"/10 = 1.8"

    Now, you are 3.6" high, divide 3.6" by 1.8" and it will tell you how many thenths (or clicks) you are high. 3.6/1.8 = 2, so it looks like you are .2 mils high. So, I guess you will need 1.8 MILS instead of 2 MILS for 500 yards. Oh, by the way, do yourself a favor and don't think in clicks, think in MILS.

    So you need 1.8 MILS, not 18 CLICKS!

    Hope that helps.

    P.S. Nothing beats putting rounds on paper to confirm, but this will get you closer to where you were before.

    -X3M
     
  7. royinidaho

    royinidaho Writers Guild

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    The group shown indicates, to me, that as you get more confidence in yourself, rifle and load plus reading conditions two shots may become sufficient. Remember that the objective is to place a cold barrel first shot at the point of aim.

    You seem to be where I was and still tend to be. Your target reveals inches (in thirds?), yards and Mils. I can't wrap my head around all of that.

    Its good that your turret and reticle are the same units Mil/Mil.

    1 mil = 3.6" @ 100yds.

    @ 500 yds 1 Mil = 5*3.6 = 18"

    Your group is about 3.666666666666667" :)rolleyes:) high.

    3.666666666666667 / 18 = 0.203703703703704 (the width of a mil dot).

    You don't have a center mil dot so ya gotta click. (I don't know the width of the cross hair)

    Go down as close as you can to 0.2 Mils on your turret. Its good to see that you are shooting well enough to see the difference in 1 click at 500. Good goin'.


    Or leave it the way is is and talk in MOE or MOD (Minute of Elk or Minute of Deer):)

    Sorry for the decimal places, I copied and pasted from the calculator, but the process reveals a bit of the way my head works which really sucks when switching from a scope that is Mil/" and IPHY/IPHY, or having to convert from MOA to Mil in the field. Which is why I said that your MIL/MIL scope is a good choice.

    I don't know where the roughly 0.1" = 0.33 mils @ 100 came from. Roughly will roughly getcha in trouble some time or another. Roughly works well in floating point math where 2 + 2 can = 5. For very large values of 2 and vary small values of 5.:rolleyes: It's not so good for LRH.gun)
     
  8. AtownBcat

    AtownBcat Well-Known Member

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    Thanks for the replys. Based on the math that you both provided the beta chrony was right on with a speed of 3145. The difference at 500 yards( between the two speed readings) was .2 mils, and that appears to be what I am high. I will test it to verify.