Long range load development at 100 yards.

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

  1. seymour fish

    seymour fish

    Joined:
    Dec 13, 2009
    Messages:
    679
    Decent from 40.5-41.5. Might look at 0.1 gr increments across the middle 2/3
     
  2. JimSC

    JimSC

    Joined:
    Jun 1, 2017
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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
  3. jp

    jp

    Joined:
    Jun 23, 2008
    Messages:
    273
    Shot this Today.. which ones would you choose? No chrony today just load and seating depths
     

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  4. abersfelderami

    abersfelderami

    Joined:
    Feb 9, 2015
    Messages:
    10
    33.2 gr / -.04
     
    seymour fish and jp like this.
  5. Rogmay

    Rogmay Gold $$ Contributor

    Joined:
    Aug 27, 2016
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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!
     
    Dgd6mm and seymour fish like this.

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