Pressure signs way below max load

Discussion in 'Long Range Hunting & Shooting' started by Mc Fraser, Aug 17, 2019.


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  1. sodakota

    sodakota Well-Known Member

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    May 29, 2014
    Switching from Hornady to Berger or to Sierra May have something to do with it.
    By chance did you slug the bore?
     
  2. Mc Fraser

    Mc Fraser Well-Known Member

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    Jul 23, 2018
    I don't know. Glass bedding was done of that makes a difference.
     
  3. Michael Cantor

    Michael Cantor Well-Known Member

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    Jan 8, 2018
    2950 is about max for a 180 from a 24" bbl, 3000 with a 26" bbl. 3100 with 215's ? That's cooking...literally. Where did you see that load info??? You should be more than happy with 3000 fps. (I'd be surprised to see that). Really, I think a 29" bbl is too long for that cartridge. I like 26" 27" may be max (without the brake). You can't turn a 3000 win mag into a RUM.
    Hodgdon lists 2950 as max with 61,000 psi with a 208 gr bullet and 24" bbl. AND that is a 81 gr Compressed load which means in your case you may nnot even be able to get that much powder in your case. You wont atuomatically get 30 fps per inch for the full 5 inches. There are diminishing returns. Back off and go for accuracy at a safe pressure.

    IMR
    IMR 8133
    .308"
    3.420"
    74.5
    2,680
    47,500 PSI
    81.0C
    2,950
    61,300
     
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  4. Frog4aday

    Frog4aday Well-Known Member

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    Oct 25, 2007
    There was a whole thread on this forum a few months ago by a gentleman trying to clean out a stubborn carbon ring from his rifle. He tried all the 'carbon' remover potions and in the end, the only thing that really worked was JB Bore Paste and scrubbing, scrubbing, and more scrubbing. Eventually he got the carbon out and the pressure issues he had went away. Some powders will lead to carbon rings faster than others. Folks will clean more frequently after dealing with a carbon ring, to avoid dealing with another one because...they are a pain.

    Here is some info on carbon rings:
    https://criterionbarrels.com/media/criterion-recommended-rifle-barrel-cleaning-procedures/
    "The Chamber
    Proper cleaning of the chamber is a critical component of a general cleaning procedure. Carbon rings can build up near the neck and throat of the chamber wall, leading to feeding malfunctions and pressure spikes inside the chamber."

    Then there is this:
    https://www.longrangehunting.com/threads/barrel-carboned-up-thoughts-on-gumout-regane.219807/
     
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  5. WYO300RUM

    WYO300RUM Well-Known Member

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    Mar 23, 2011
    I don't have my glasses on and don't feel like getting out of bed to get them but is that a crack by the firing pin hole or scratch or gouge ?
     
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  6. FEENIX

    FEENIX Well-Known Member LRH Team Member

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    I noticed that too!
     
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  7. Lycanit

    Lycanit Well-Known Member

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    Nov 6, 2015
    Definitely looks like a gouge.. with the deepest ending over the edge of the hole. What is the hole width vs pin diameter?. Your primers look good aside from cratering. Maybe try Wolf?
     
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  8. 73driver

    73driver Well-Known Member

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    Aug 24, 2011
    I just read the whole thread and some good points came up. The FIRST easy answer is the gunsmith who posted about a min chamber. Pick one bullet and one powder to work with starting at min recommended load (detonation issues I believe come up at below published min charges). With min loads and working up look for normal MV for that bullet and accuracy nodes. If min loads go over normal MV's then scope the throat area. hope this helps
     
  9. skipglo

    skipglo Well-Known Member LRH Team Member

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    Jan 23, 2015
    That is FAST but I'm thinking the 29" barrel would add approximately 150 fps max to the published loads as many are shot with 24-26" barrels. Still no excuse for pressure though. But I would still suspect seating a bigger issue!
     
  10. Mc Fraser

    Mc Fraser Well-Known Member

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    Jul 23, 2018
    Update: Smith believes it is the spring that holds the firing pin in place, we change it and no I have to go to the range to test the theory.
    If he is right it is amazing how his methodology is ... he literally circled the gun and he's like yea ... you hear that ...
    Me: ?!?!?!?!
    After he changes the spring: much better now can you hear it?
    Me again: ?!?!?!?!
     
  11. CVCOBRA1

    CVCOBRA1 Well-Known Member

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    Sep 20, 2014
    Did he say anything about the firing pin hole in the bolt face? I'm sure you showed him some fired cases.
     
  12. Mc Fraser

    Mc Fraser Well-Known Member

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    I had 2 fresh fired cases with me and he said that we might have to put a bushing on the hole. One step at a time basically.
     
  13. Lycanit

    Lycanit Well-Known Member

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    Nov 6, 2015
    My thoughts were bushing the pin hole.. buuuttttt..
    I'm old and what do I know
     
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  14. Paper boy

    Paper boy Member

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    Jul 18, 2019
    Rifles are like people, no two are exactly alike.
    One of the many things many shooters forget is the age, or condition of the rifle chamber itself.
    If you rifles chamber is a bit worn or "over sized fron wear" it will show pressure signs much sooner than you may think. A worn chamber allows the case to expand beyond it's design limits, check your chamber readings by a reliable gunsmith. This could save you and your rifle a lot of time or possibly injury from an exploding case. CAUTION IS NEVER OUT OF PLACE.