Long range load development at 100 yards.

Discussion in 'Reloading Forum (All Calibers)' started by Erik Cortina, May 5, 2013.

  1. JimSC

    JimSC

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    I did a load test yesterday on Sierra 142's with H4831SC in a .260 Remington with a new 100 round count 30 inch Shilen 1 in 8 twist barrel. Due to a chrono error at 43.3 and 43.6 I have no data. but the following velocities were recorded

    43.9 gn 2749 FPS SD 49
    44.1 gn 2762 FPS SD 35
    44.4 gn 2769 FPS SD 7
    44.7 gn 2804 FPS SD 18
    45.0 gn 2816 FPS SD 11
    45.3 gn 2818 FPS SD 32

    seating was at 2.250 base to ogive and .025 off lands.

    I will only have one chance to do a seating depth test before a 800 yard match should I test depth test @ 44.4 which had the lowest SD or 45.0 which had a slightly higher SD but the test groups between 44.7 and 45.3 only had a 14 FPS differential. The alternative would be leaving the depth at 2.250 and doing a velocity test using 44.3 - 44.4 - 44.5 and a velocity test using 44.9 - 45.0 - 45.1

    Targets were shot in the afternoon at 88F and a heavy boiling mirage with 0 - 3 mph winds. Not my ideal testing environment but I had to work with what I had after a solid week of rain

    thanks in advance for any replies

    4831_1.jpg

    left side on target 2 was cut off on the scanner, top is 44.4 and bottom is 45.0

    4831_2.jpg
     
    Last edited: Aug 6, 2018
  2. jp

    jp

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    Shot this Today.. which ones would you choose? No chrony today just load and seating depths
     

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  3. abersfelderami

    abersfelderami

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    33.2 gr / -.04
     
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  4. Rogmay

    Rogmay Gold $$ Contributor

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    33.2 @ .011, the jammed group shot a little high, the next three you can stack on top of each other, take the one in the middle!
     
  5. lazyMlazyK

    lazyMlazyK

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    Shot the .22-250 at 322 yards last night. 13 rounds, starting at 36.3 gr. H380, ending at 39.9 gr. Worked up in 0.3 gr. increments. Bullet was Nosler Varmageddon 55 gr. flat base ballistic tip p/n 17240. Was not shooting groups, just a ladder. What are your thoughts? I’m thinking 8, 9, and 10, or 11, 12, and 13 look like nodes? Chrono wasn’t working or I would have velocities to add here as well.
     

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    Last edited: Oct 27, 2018
  6. daniel brothers

    daniel brothers Silver $$ Contributor

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    I’m thinking 8, 9, and 10
     
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  7. SGK

    SGK Silver $$ Contributor

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    Sample sizes of 1. What do you expect those samples to tell you about how/where your rifle shoots and with what degree of confidence?
     
  8. lazyMlazyK

    lazyMlazyK

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    Just hoping to narrow down a starting point for load development. If load 9 tells me I might have some decent grouping, I can load up 3-5 rounds of load 8, 9, and 10 to continue development. Is that a bad method? I’ve always just started by shooting groups in 0.5gr increments but wanted to try something different. Isn’t this type of ladder test supposed to give a guy an idea of where accuracy nodes might live for a certain gun with a certain load, even with a sample size of 1?
     
  9. brians356

    brians356 Gold $$ Contributor

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    I don't subscribe to this method, but I understand the concept. In that context, 8-9-10 shows promise to this jaundiced eye. Now, move on to the real testing, starting there.

    PS This is not the method for which Erik Cortina started this thread.
    -
     
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  10. lazyMlazyK

    lazyMlazyK

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    Sorry, thought that was obvious. Seemed like a good place to put it though as it relates SOMEWHAT to his method.
     
  11. brians356

    brians356 Gold $$ Contributor

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    There are no fewer than 37 threads with "ladder" in the subject, in 2018 alone (!), any of which would probably be more apropos. Plus this thread is now up to 104 pages. Yikes! o_O
    -
     
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  12. seymour fish

    seymour fish

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    8-9-10
     
  13. brians356

    brians356 Gold $$ Contributor

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    Also FWIW, Erik Cortina himself hasn't commented here in over three years.
    -
     
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  14. Ned Ludd

    Ned Ludd Silver $$ Contributor

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  15. SPJ

    SPJ Silver $$ Contributor

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    German Salizar is absent as well.
    What to know why?
     
  16. dstoenner

    dstoenner Silver $$ Contributor

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    OK, I give

    David
     
  17. SPJ

    SPJ Silver $$ Contributor

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    Too much negativity and BS
     
  18. Ccrider

    Ccrider Silver $$ Contributor

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    Wow. I guess some people don’t understand the irreplaceable value of sage advice.
     
  19. Kurt Blasser

    Kurt Blasser Gold $$ Contributor

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    Shot this yesterday. Would like comments regarding which load would be best. Shot Cortina technique with 200.20x, Varget 43.0 through 44.8 in .2 gn increments, 30 inch 1-10 twist barrel. Bullet seated .020 off jam.
     

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  20. oldduc

    oldduc Silver $$ Contributor

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    I like #8. It's the flattest.
     

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