338-378 weatheby handloads

338weatherby

September 14, 2011 14:02

I got a recipe out of a Sierra publication that I tried. It is shown as a max load and is as follows:

250gr Sierra Gameking with 115grains of Retumbo by Hogden with a Federal 215 primer. MV listed as 3200FPS

The bolts sticks often and the cases show signs of too much pressure. What would be the best reduction (%) to start with to make a viable load using these same components?

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  rordog

  September 14, 2011 16:09

  Reduce by 10% and work back up.

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  md1634

  September 15, 2011 07:08

  At least 10%.

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  nononsense

  September 15, 2011 15:29

  338weatherby,
  
  While the overall reduction of powder is a standard response to any sign of pressure, I would try to see if there was another cause perhaps.
  
  1) What brand of rifle?
  2) What brand of barrel, factory or custom?
  3) Is the neck crimped?
  4) What is the overall length and are you jammed into the lands?
  5) Did you check the scale you used for accuracy?
  6) What signs of pressure are the cases showing?
  7) What do the primers look like?
  
  Best.

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  tsr1965

  September 16, 2011 01:45

  338 Weatherby,
  
  First off, I am going to tell you, to NEVER start off with a published maximum load. That is a very bad practice. All rifles, and test barrels are NOT created the same.
  
  Because that points to the sign of being young in the handloading field, I will ask, did you check the length of your cases? Have they been trimmed to proper length? If the case necks are to long, when you cam the bolt closed, you can actually crimp the case mouth into the leade of the throat. This literally gives the case mouth no space to open uo to release the bullet.
  
  Now I would check that, and trim to the recommended trim length. Start back at the starting load and load 5 rounds, and slowly work up in 0.5 grain increments, untill the primer just starts to flatten. Then you are at the maximum of your rifle, not the maximum of the published book.
  
  As always, nononsense lays down excellent advice too.
  
  Best

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