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Thread: signs of high pressure

  1. #1
    Senior Member NAPOTS's Avatar

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    signs of high pressure

    I noticed flattened primera on my last batch of ammo when i went to size and deprime them. The cartridge is .308 win and the load is varget behind a 168 gr bullet. I didnt list charge because im not sure if that is againt forum rules or not. the load is within the limits in my reloading manual but a bit on the higher end. The firing pin indentation is a bit cratered too. I guess i have to reduce my load which sucks because this load is super accurate. Has anyone else had any experience with high pressure problems? Should i be concerned with rest of the ammo i have loaded up?

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    Team GunsNet Gold 07/2012 / Super Moderator Gunreference1's Avatar

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    The Hodgdon website lists two loads using Varget powder with a 168gr. bullet. Both have a 2.800" COL with the case trimmed to 2.005".

    168 GR. BAR TTSX BT - Max Load 45.0 grains

    168 GR. SIE HPBT - Max Load 46.0 grains

    But each gun will be different because each chamber & barrel combination will have it's own characteristics. Based on the symptoms you've described you probably need to back off at least one or two grains from whatever you're using now. And for your remaining loads I probably would pull the bullets and lower the powder charge to remain safe. Just my $0.02.

    Steve
    After today, it's all historical.

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    Senior Member NAPOTS's Avatar

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    my load is less than 45 gr.

    Am I reading too much into the primer? maybe they are just soft? I thought the manuals were very conservative?

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    Team GunsNet Gold 07/2012 / Super Moderator Gunreference1's Avatar

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    Please remember the Hodgdon data also shows using a 24" barrel with a 1 in 12" twist. My bet is your rifle has a 1 in 10" twist? You can try different primers to see if that's the problem. Also, are you seeing any issues with the cases or extraction issues?

    Steve
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  5. #5
    Senior Member NAPOTS's Avatar

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    I don't think I'm seeing any case issues. Im shooting them through a bolt gun so its kinda hard to say on extraction issues. Twist is 1:12 barrel is 26"

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    Team GunsNet Gold 07/2012 / Super Moderator Gunreference1's Avatar

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    Your next step then would be to put aside the remaining loaded ammunition and reload those with primer issues with a different primer and the same amount pf Varget powder and same bullet. Then shoot those loads and see if the same problem occurs.

    Steve
    After today, it's all historical.

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    Forum Administrator Schuetzenman's Avatar

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    A Photo would help in telling the tale. As far as a little flat, not a problem if it is not too flat. When you say cratered do you mean a raised ridge of metal around the firing pin strike? This is why I say a photo / photos would be very helpful in knowing if you are really close to the edge on pressure. What brand of primers? Some are softer than others, Winchesters are by rumor on the soft side.

    I get worried when primers get pierced, but a touch of flattening with a dab of crater isn't a fatal thing IMO.

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    Senior Member NAPOTS's Avatar

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    Primers are winchesters. Different gun but I was getting pierced primers on one of my ARs, it ended up being a burr on the firing pin. I pierced 2 boxes of ammo and didn't notice until I went to reload the brass.



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    Site Admin & **Team Gunsnet Silver 12/2012** Richard Simmons's Avatar

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    What brand is your rifle? Was reading on another forum that cratered primers are common with Remington as they have a slightly larger firing pin hole which allows the primer, especially a soft one to flow back into the hole and leave a crater.

    Look here.

    http://forums.1911forum.com/showthread.php?t=414621
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  10. #10
    Senior Member NAPOTS's Avatar

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    Richard, it is indeed a Remington.

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    Forum Administrator Schuetzenman's Avatar

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    I assume that is a primer from the target of this discussion. I see the cratering, but what I don't see is square sharp edges at the perimeter of the primer cup. I see radius and to me that says the pressures are OK. When you really have pressure you will have 90° squared shoulders on the primer cup, no radius left. Also, you will see the impression of the tooling marks on the face of the bolt embossed into the primer metal. I don't see that on your primer. I think Richard has found the answer here, large FP hole in the Remy bolt.

  12. #12
    Senior Member NAPOTS's Avatar

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    The primer is a lot more "square" than it is before it is fired.

    Sorry to bug you guys with this, the manuals make such a big deal about watching for high pressure signs and when I saw these I was afraid I messed up. I try to be very careful with my reloading and follow the manuals to a tee.

  13. #13
    Forum Administrator Schuetzenman's Avatar

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    Quote Originally Posted by NAPOTS View Post
    The primer is a lot more "square" than it is before it is fired.

    Sorry to bug you guys with this, the manuals make such a big deal about watching for high pressure signs and when I saw these I was afraid I messed up. I try to be very careful with my reloading and follow the manuals to a tee.
    No problem, I don't consider this "bugging" by any means. I've been reloading for 41 years, seen a lot of things. Example load developed in November and virtually no pressure signs on the primer but same ammo shot in July, big pressure signs and a sticky bolt handle and extraction. Speaking of which, did you experience any issue in lifting the bolt or pulling it back to eject the fired case? Once again if it went smoothly, I'd say no excessive pressure signs. Your primer may be more square at the shoulder after firing but it isn't 100% squared off and I see no tooling marks in the primer. To me that says pressures are OK. If you are below max load by over a grain there should be no reason to have high pressure signs and what you have I do not consider to be high. The only thing that would make me look twice is the ring around the primer hit. Still that isn't anything fatal unless the primer is failing.

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