neck tension

Discussion in 'Reloading' started by col48, Aug 6, 2006.

  1. col48

    col48 Well-Known Member

    Messages:
    261
    Joined:
    Feb 17, 2006
    i have been sizing my cases as far down as my die will let me,(redding competition neck die)1 am putting about 3" neck tension on them.if i only neck size 1/2 way down my cases,
    how much difference will this make to my groups????
    this is in a full custom rifle built by nesika,all but the bedding.
    only i did this yesterday and my groups opened up to a inch.

    i am starting to think that my rifle has not been bedded properly,as the 4 that have been done are not shooting to what i would call there full potential.we seem to be lacking consistency.one day i will shoot a .3 the next day it will shoot a 1" @ 100y.
    so today i think i am going to rip out the bedding and do them both myself.

    i put her through the crono yesterday and got

    # 1 3270.6
    # 2 3300.5
    # 3 3300.5
    # 4 3308.4
    # 5 3320.4
    # 6 3297.9
    # 7 3299.2
    # 8 3305.8
    # 9 3309.8

    sd: 13.5
    cv: 0.4%
    mad 8.6 fps
    cv 8.3%
    av 3301.5 fps
    es 49.8 fps

    high 3320.4 fps
    low 3270.6 fps

    270 WSM shooting 135g SMK n165 66.2g temp 72 D/F.Norma brass,minimum SAMMI spec chamber,3thou of expansion on the necks (no neck tern) 26" lilja bbl.
    1/2 to 3/4 thou concentricity
    /ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/confused.gif
    thanks
    Colin