Sierra TMK?

Discussion in 'Reloading' started by cornchuck, May 17, 2015.

  1. cornchuck

    cornchuck Well-Known Member

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    I finally got to load up some 175 gr. Sierra TMK's for a OCW test for my factory Rem 700P. I load all the ammo for this gun to fit the mag and when I determined the length for these bullets, they are really in the case. What I came up with was an COAL of 2.824 and CBTO of 2.089. My load for this rifle is 175 gr. SMK with an COAL of same measurement as the TMK and CBTO of 2.227.

    About half way through the seating process, I was thinking I am getting into compressed loads(41.5-44.2 grs. of Varget going up .3 gr.). I couldn't hear the powder shaking in the case any more. But couldn't hear or feel the powder crunching.

    I know Remington's have long throats. Am I going to get some trouble with these? What are other shooters seeing for their seating depth?

    Jason
     
  2. cornchuck

    cornchuck Well-Known Member

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    No one has an opinion?

    Jason
     
  3. jfseaman

    jfseaman Well-Known Member

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    I have no hard data to reference but the pictures indicate a completely different bullet shape. The SMK is a tangent ogive and the TMK appears to be secant. I think the TMK is longer than the SMK.

    This could indeed cause high % of case volume used by the bullet, causing compressed loads aka higher load densities. This could lead to pressure problems.

    Better to error on the side of caution, I would back your load down and work back up.

    If you would please, measure the length of the SMK and TMK.
     
  4. cornchuck

    cornchuck Well-Known Member

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    jfseaman,
    Thank you for replying to my post. Sorry it took longer than it should have to get back with you. I have been busy at work.

    I did measure the SMK and the TMK like you asked.

    SMK TMK
    Total length 1.242 1.385
    Base to Ogive .665 .651

    After racking my brain for a few days about my test loads, I have decided to pull the bullets and seat them longer than I would like. Yes they will not fit the mag. If I find a load I like, then I would most likely put a Wyatt's extended box on.

    Jason
     
  5. cerralvo78

    cerralvo78 New Member

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    deleted post because it was duplicated
     
    Last edited: Jun 13, 2015
  6. cerralvo78

    cerralvo78 New Member

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    Hello...I am new to this forum
    I was looking also info online on the .308 win 175 TMK
    I got a box at my local shop
    RIFLE DPMS LR308 24" BARREL

    I loaded them with my 175 SMK load:(lapua 2.005, Varget 43.6, 175 SMK, 2.230 CBTO or 2.815 COAL)
    on the TMK I use 2.800" coal and pour 43.6V........When I load the first round i heard the crushing sound...........
    I stop
    Then I decide to test on the capacity of my ammo,
    Lapua brass 2.005", 175 TMK(base to ogive .656"), varget powder, 2.800" coal

    40.0gr varget did not compress(I hear the powder shaking)
    41.5gr varget did not compress(I hear the powder shaking)
    42.0gr varget IT DID COMPRESS(I couldn't hear the powder shaking)


    Max COAL on my DPMS is 2.825 with a 1.380"(base to tip) 175 TMK bullet
    My max COAL will be 2.820" to cover for length imperfections(1.375" to 1.384")
    My max COAL (DPMS max to lands) is 2.980"

    Ladder indoor at 25 yards (no POI info only test for velocities and pressure signs)
    175 TMK/fm lapua brass 2.005"/WLR/varget powder/COAL 2.820"/2.100" CBTO

    Varget/SPEED
    39.4 2371
    39.7 2422?????
    40.0 2417
    40.3 2486
    40.6 2444 ?????
    40.9 2487
    41.2 2517
    41.5 2529

    I DID NOT SEE ANY PRESSURE SIGNS
    I WILL LOVE TO HAVE A ROUND 2650 FPS ON THIS BULLET

    MY QUESTION IS....WOULD IT BE OK TO GO ANY HIGHER THAN 41.5??
    I WILL DO A POI LADDER TEST LATER AT 400YDS

    THANKS
     
  7. tbrice23

    tbrice23 Well-Known Member

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    I've found Varget likes compression in a few different cartridges , however in gas guns watch for early pressure signs because of the hot chamber unless you are going to single load during load development.
     
  8. cerralvo78

    cerralvo78 New Member

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    THANKS....
    I am single loading
    I have heard that varget likes compression,
    NO pressure signs.....Im going to go up just a little bit a few more increments, and look at any early pressure signs
    THANKS again.....I will post results.....it is perty wet here in houston area, hopefully we can get some decent weather soon!!
     
  9. Clutch0733

    Clutch0733 New Member

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    Found a decent 175gr TMK load with 41.8 of 4064, seated to 2.870 COAL. It's a whole new VLD type bullet, so more seating deprh sensitive than the SMK.