.243 Win data

laylandad

October 12, 2009 16:31

I've worked up to a really good load in the Speer #13 manual using a 90gr Speer spitzer SP with 38.5gr of W760 with CCI 250 primer. I have noticed that cross-referencing data from the powder manufacturer, Speer seems to be a little underloaded. The #13 has a starting load of 37.0 gr of W760 and max of 41.0gr with a magnum primer. Hodgdon website has the starting load at 41.0gr and max of 43.5 with standard LR primer. Who is right? Is it safe to continue to use the Speer data? Is the difference in the data the primer?

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  JustC

  October 12, 2009 16:34

  different test barrels used in the process yields differing chamber pressures

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  Mobuck

  October 14, 2009 17:58

  I've started using a
  Chrony as part of my load workup. When I get the velocity listed I stop regardless of whether I've reached the listed max. If I start getting pressure signs before reaching that velocity, I switch powders. I used to study primers and bolt resistance but I've got too many variables these days. The last 5-6 loads I've worked up achieved listed velocity below the listed max and a couple of those with barrel length shorter than the manual's.

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  laylandad

  October 16, 2009 06:56

  Thanks!!

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