Jacket Stress Measurement/Calculation????

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by royinidaho, Dec 29, 2008.

  1. royinidaho

    royinidaho Writers Guild

    Jan 20, 2004
    This is a 2004 post from David Tubb over on another forum. Googling came up with it.

    Why dont the 115 Bergers shoot? - because of jacket stress.
    Jacket stress (in 1000 psi or 1K) gives stress values which arent the same as gas pressure values.
    The 115 Sierra has a jacket stress value (maximum chamber pressure) of 60ksi. The 107 Sierra has a lower ksi at the same pressure levels (56ksi). The Berger 115 VLD exceeds 85ksi in same type pressure environment.
    This means that the Berger 115VLD is distorted in the barrel and/or while exiting - thats why they dont shoot very well. DTubb

    What in the world is David talking about?

    Edit: Don'tcha hate when ya hit submit post the next search gets ya what you were looking for?

    It seems that a bullets ability to handle "jacket stress" is quite important. I've learned that some bullets won't hold up under stressful bore conditions such as high velocity, fast twist and rifling configuration/type. I know what doesn't work but am researching the "why" for another one of my seemingly never ending boondoggles.:rolleyes: I may as well not create another bullet that doesn't work, or I'd like to minimize the odds of that happening.:)

    Link to the whole thread: http://www.6mmbr.citymaker.com/board/board_topic/1311246/58922.htm

    Any further insight on jacket stress calculations would be appreciated.

    Don'tch hate it when ya hit submit then find the info that gets ya jump started?:rolleyes:

    Wrap your head around this: DTAC 6mm 115gr Specifications

    But still don't know and probably can't handle the calculations..........
    Last edited: Dec 29, 2008