Spherical powder worse for throat erosion??

Discussion in 'Reloading' started by snider6464, Jan 8, 2011.

  1. snider6464

    snider6464 Member

    Nov 30, 2010
    I have a 30-378 Weatherby, and im trying to get the full life out of the barrel. So i have been reading around on things to do to help keep the throat and barrel from having a short life.
    I read someone saying to stay away from spherical powder because it causes more throat erosion.
    Is this true? and if it is why? Also any other tips you have on keeping my barrel in good shape would be more than welcome. Thanks guys
  2. RockyMtnMT

    RockyMtnMT Official LRH Sponsor

    Mar 25, 2007
    I believe that it is the other way around. The spherical is less damaging. If I understand correctly it is because it slides out easier and does not bridge. I am sure that someone smarter than I will explain it better.

  3. Loner

    Loner Well-Known Member

    Apr 14, 2010
    One of the later theories is that granular powders being pushed into the throat
    by the explosion at the back of the case do some eroding and of coarse are burned
    there as well. Putting a primer tube in the case so it ignites the powder from the
    neck first lengthened throat life so it seemed testing bore it out. You have a cartridge
    that is going to produce about 600-800 rounds before the throat erodes enough
    for you to notice a change in accuracy. Keeping your loads backed off from maximum
    will do more to insure that than powder choice in my opinion.
  4. Trickymissfit

    Trickymissfit Well-Known Member

    Jun 11, 2010
    with smokeless powder there is no explosion like there is with black powder. The bullet moves via pneumatics. But then there is a much higher concentration of heat build up verses the older stuff. You take that into fact along with much larger amounts of powder, and you are ending up with a flame that is higher than the melting point of the steel itself. A 40 degree shoulder will help fight off barrel errosion assuming there is an ample amount of neck length to contain the vortex of the flame inside the neck instead of ending up in the throat like some many short necked cartridges are. Ideally you want the vortex of the flame in the first half of the neck (furthest away from the throat). A typical Weatherby case will compute out at about 48 degrees by the way.

    As for backing off the loading on a 378 case; that can be a very bad thing! Those big cases don't like this, and are at their best at near max loads