Need help with velocity measurements.

Discussion in 'Reloading' started by jsimonh, Oct 3, 2010.

  1. jsimonh

    jsimonh Well-Known Member

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    Jul 27, 2010
    I'm having a little problem figuring my velocity for my .270.

    Specs: Sendero w\26 inch 1:10 twist barrel.

    I loaded up 59.5grs of H4831sc which is a half grain under max and avearged 3140fps for 5 shots. In my manual and the Hodgdon website 59.9grs should yield a velocity of 3010.

    Also I loaded up some 150gr Berger VLD's with 57gr of H4831sc which yielded a 5 shot average of 2963fps. The Berger load data has 57.5gr as max load with a velocity of 2899 out of a 26" barrel.

    I tested the Chrony with HV .22 bullets and it avearged about 20fps less than what was advertised on the box, so I think the chrony is fairly accurate.

    I'm still pretty new in the reloading game, and I'm just wanting to make sure that my info is correct. I just don't see why my velocity is so much higher than the max listed and I'm using less powder to get them.

    Any Ideas?
     
  2. Gunpoor

    Gunpoor Well-Known Member

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    Apr 28, 2007
    Every barrel reacts differently to a load. Most of the time my results are slower than the posted loads. That is why loads need to be "worked up", because each particular barrel is slightly different than any other barrel ever made. Sort if like fingerprints, every one is different. Anyway, you should be completely elated that your rifle shoots like it does, that is if it is also accurate!
     
  3. jsimonh

    jsimonh Well-Known Member

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    Jul 27, 2010
    Thanks for the reply. The SMK's didn't group worth a crap, but the Bergers gave me 1/2 inch 5 shot group at 115 yards. I was pretty satisfied.
     
  4. Moman

    Moman Well-Known Member

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    Feb 7, 2008
    Sounds like you may have a good load worked up. When you shoot it long range you will be able to test your drops for that velocity and then you'll know if they're accurate. If using Exbal, it's easy to validate your load.