Pressure signs way below max load

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


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  1. Joefrazell

    Joefrazell Well-Known Member

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    That's gotta be the longest win mag throat ever to be cut.
     
  2. Mc Fraser

    Mc Fraser Well-Known Member

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    I don't believe I made an error, I measure it with 2 different techniques and by a gunsmith as well.
     
  3. Joefrazell

    Joefrazell Well-Known Member

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    Mine is like 3.7 coal with a 215 Berger and that was with a factory chamber. Could be but that bullets jumping a mile
     
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  4. Joefrazell

    Joefrazell Well-Known Member

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    I don't know why a Smith would throat it that long but who knows
     
  5. FEENIX

    FEENIX Well-Known Member LRH Team Member

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    Something is definitely wrong with the numbers above. I am looking at my Hornady for 212 ELD-X and 3.34" is the recommended COAL, this is "not" the same as CBTO.

    I think you're measuring your CBTO with the gauge insert; 3.750' - gauge (normally 1.00") = 2.750" which makes sense. To measure the COAL, remove the remove the insert, zero the caliper and measure from base of the brass to the tip of the bullet.
    This is my .300 WM with 200 NAB...

    COAL CBTO 1 of 3.jpg
    COAL CBTO 2 of 3.jpg
    CBTO

    COAL CBTO 3 of 3.jpg
    COAL
     
    Last edited: Aug 17, 2019
  6. Mc Fraser

    Mc Fraser Well-Known Member

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    I only use CBTO for Berger bullets, for Hornady and Sierra bullets I use COAL.
    COAL for 212 Eld-x is 3.5in
     

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  7. FEENIX

    FEENIX Well-Known Member LRH Team Member

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    I got that part, but your 3.750" CBTO remains a mystery, look at my pictures that I added.
     
  8. Mc Fraser

    Mc Fraser Well-Known Member

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    Thanks. That is exactly how I measure as CBTO and COAL.

    It might just be that my rifle builds pressure faster than other rifles and I have to slow down my loads. Who knows? So far the only potential red flags that I could think of are: the original barrel was a 4R this one is 5R and the fact that the throat is longer than most of the rifles.
     
  9. DT400

    DT400 Well-Known Member

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    Something still doesn't make sense.
    CBTO can not be longer then COAL.

    Darrell
     
  10. Mc Fraser

    Mc Fraser Well-Known Member

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    You are right, I apologize or the typo error, should be 2.7500 instead of 3.7500.
     
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  11. DT400

    DT400 Well-Known Member

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    One mystery solved...now back to our originally programmed mystery.

    Darrell
     
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  12. FEENIX

    FEENIX Well-Known Member LRH Team Member

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    If you have a CBTO of 3.750" that means you have over 4.00" of COAL. Can you show us a picture of your COAL like the last picture I have. As you can see I am not the only one that is puzzled with your claim.
     
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  13. FEENIX

    FEENIX Well-Known Member LRH Team Member

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    Agreed!
     
  14. DT400

    DT400 Well-Known Member

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    Do you have a buddy with a COAL tool? Not the Hornady Comparator but the COAL tool that uses a special cartridge case and the bullet of your choice to measure YOUR exact cartridge base to lands inside the gun.
    https://www.midwayusa.com/product/1012747079?pid=570611
    I am wondering if your chamber is actually shorter than spec and you are in the lands. The sharpie method isn't the best by a large margin.

    Darrell
     
    Last edited: Aug 17, 2019
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