Primer Question

Discussion in 'Rifle Cartridge Data' started by histed, Sep 17, 2016.

  1. histed

    histed Supporting Member

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    I'm working with W760 powder and Hornady 95 grn SST bullets in a 243 Winchester. Not happy at all with results to date. Very erratic, stringing. and generally large groups. I've been using CCI 200 primers. Since this is a ball powder, should I be using 250 magnum primers? Any experience with this?
     
  2. Quavodus

    Quavodus Member

    I don't have my loading manuals handy now but, W760 is a little on the slow side. You could try CCI 250's and see how they work. Watch for pressure signs. I almost never use Magnum primers. I shoot a lot of IMR 4350 and just use CCI 200's. I also shoot a lot of W748 and just use CCI 200 or Federal 210. Some loading manuals recommend magnum primers with ball type powders. Let us know if you get better results.
     

  3. histed

    histed Supporting Member

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    Finally got out to the range yesterday. I shot differing weights of W760, RL22, and H4350. Every powder turned in better groups with CCI 250 magnum primers. H4350 had NO bad groups - the biggest was just 7/8 at 100 yards, the smallest was 3/8. RL22 worked best neat maximum, with groups between 5/8 and 1". I shot 5 shot groups with 760 (I have more of that) and got interesting results. First three would always be fairly tight, four would open the group and five increased to 13/8 to 11/4" every time. I'm guessing heat, since I didn't see this with three shot groups. I have four more powders to try, but expect similar results. Conclusion - in THIS rifle (Savage Axis, south-paw), magnum primers do make a difference. As always, YMMV.
     
  4. Thanks for reporting your results. I'll keep this in mind as something to try if I'm having a problem.
     
  5. undeRGRound

    undeRGRound ROLL wif Da MOLE! Supporting Member

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    CCI 250 primers. Noted ;)

    Large Magnum.