104% of what?

Discussion in 'Reloading' started by Greg Duerr, Apr 7, 2013.

  1. Greg Duerr

    Greg Duerr Well-Known Member

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    I was looking at the Berger Manual and it showed the .243 and the 95gr with a load of 48.3gr of H1000 It said 104% what does that pretain to?

    When would you know if your case is at 100% Is that up to the top of the neck? How could you go past that?

    What is capacity? Do different powders have different capacities??
     
  2. barnesuser28

    barnesuser28 Well-Known Member

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    case fill, with the bullet seated to that depth that powder charge is compressed. Some powders are "bulkier" than others so they take up more room and have a lesser charge weight.
     

  3. metalhead

    metalhead Well-Known Member

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    It's a reference to "usable" case capacity. Case volume is measured in grains of water. Usable capacity is total volume minus the space of a bullet seated to SAMMI specs. The resulting number is then referred to as 100% usable case capacity. Your % will be over 100 when the charge exceeds this volume. Simply put you'll have a compressed load and several manuals simply say compressed instead of using a %.
     
  4. Greg Duerr

    Greg Duerr Well-Known Member

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    So in the Berger Manual 104% was still safe...............................I know that when i WAS loading with H1000 the charge was up into the neck.................I got the impression that with the .243 it would be hard to over charge. Im sure the Berger manual has it in the safe range still at 104%
     
  5. metalhead

    metalhead Well-Known Member

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    Just follow the cardinal rules of reloading. Start low and work up, watching for signs of pressure.
     
  6. CogburnR

    CogburnR Well-Known Member

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    The max listed is not to be used as a SAFE RANGE.

    The max listed load is where the cartridge used and components used reached the maximum SAAMI working pressure for that cartridge in that test barrel.

    Some individual rifles may reach maximum pressure before the maximum listed load is reached. Other rifles may allow the loader to exceed the maximum listed load safely.

    Also, fired cases and different brands of cases may have more or less capacity. It all makes a difference.

    The 104% charge of case capacity means the particular cases used with the bullet used at the overall length used had a certain measured capacity and the powder charge exceeded that capacity. The charge would be compressed.

    I have seen where a listed over capacity load wouldn't even fit in a case without a bullet. Many of these loads if used need to be charged with a dropper tube while dumping the powder to create a spin in order for the powder charge to fit.
     
  7. xdeano

    xdeano Well-Known Member

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    I'm at 106% with H1000 in the SLR with no pressure signs at all with 47.4grns. It is a compressed charge but shoots excellent. I'd still say work up the load to that compressed load, definitely start lower.

    xdeano