Question on Sierra 69 GR .224 Matchking bullets

Discussion in 'Ammunition & Reloading' started by DAB, Apr 1, 2011.

  1. DAB

    ydnaS nogerO
    New Member

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    Please read carefully

    .224 Sierra 69 GR. Matchking ?????

    To start with all my measurements are from Base of case to Ogive of bullet. My press is tight no slop, my dies are adjusted properly. Using the same shell holder for all stages.

    Loaded up 20 rounds of the Sierra 69 GR MK. The seating depth is varying from the shortest to the longest 0.010 inches using Hornady seating dies. So I thought I would change to my RCBS seating dies and seat the bullets down another 0.005 Inches starting with the shortest cartridge. Well I get the same results, from the shortest to the longest it is still varying 0.010 inches.

    I am wondering what is going on so I measure a few bullets out of the box. From base to tip of the bullet varies 0.001 Inches on the ones I measured. Then I measured from the base of the bullet to the Ogive of the same bullets and got a spread of 0.005 Inches.

    This all got me to wondering about the Sierra 52 Gr. Matchking loads I already have loaded up setting on the shelf. I go grab 5 rounds and measure them, what a surprise! the 52 Gr Matchkings only varied 0.001 inches from base of case to Ogive.

    At this point I am thinking that Sierra's quality control is slipping at least on the 69 Gr Matchkings.

    Have any of you seen the same variation of 0.010 inches give or take when loading any of Sierra's Matchking bullets measuring from base of case to ogive of the bullet of a loaded round????

    I am using Hornady Lock -N - Load bullet Comparator tools for measuring.

  2. PBinWA

    Clark County
    Well-Known Member

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    I've noticed that my RCBS seating die isn't as consistent as my Lee die. I just use the Lee dies all the time now and they are fairly consistent for me once everything is dialed in. Just my observation - I'm no expert.

    I'll try and measure some of the .69Gr. SMK's the next time I'm loading.
  3. Mark W.

    Mark W.
    Silverton, OR
    Bronze Supporter Bronze Supporter

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    variation can also be due to the elasticity of the brass. I see the same thing with almost all rifle ammo I load.

    Minor varitations in brass neck lenght will also contribute to variations in bullet seating depth.

    Are your OAL's varying? as much?

    have you pulled your seating die apart and cleaned any residue on the bullet cup?
  4. jer fly

    jer fly
    cottage grove

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    Just a thought. I had the same problem with another round, turned out to be primer protrusion, not the bullet.

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