H50BMG in .338 lapua Improved ???

Discussion in 'Reloading' started by duster, Mar 28, 2010.

  1. duster

    duster Member

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    I am surprised that more .338 Lapua Imp. shooters are not using H50BMG with the 300 grain Sierra. Mine Lapua is the 40degree version and I have regularly achieved 2950 fps, extreme spreads in the single digits, and excellent accuracy. Perhaps my experience is unique.
    What experience have others had with this powder in the Lapua with 300 grainers and what powder do you prefer.
     
  2. jmden

    jmden Well-Known Member

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    What's your barrel manufacturer and length? Grains of powder? Is this load compressed? OAL? Any pressure signs at 2950?

    Queries about this powder on this site with 338 Lap Imps have typically been answered with a 'this is too slow of a powder for that chambering', but I've been curious about it regardless and also have several lbs. of H-50BMG to burn...

    Thanks for your info.

    Jon
     

  3. duster

    duster Member

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    My barrel is a Broughton 5C, 32 inches long. The load I have been using is 110 grains. It is slightly compressed since the powder comes up to the shoulder of the case and the bullet base ends up about a quarter of an inch below this point. So the load is compressed in the area occupied by the base of the bullet, but at the same time the powder is free to go into the space between the shoulder and the neck of the case, so compression is minimal. Still I would have to say load density is at least 100%
    I load touching the lands. There are no pressure signs. Extraction is easy. And I have not encountered the fouling mentioned by some others.
     
  4. Tyler Kemp

    Tyler Kemp SPONSOR

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    I use Retumbo in my 338 Lapua Improved, 100 grains is the usual load, for 2975 fps. It's a 32" Broughton barrel. I went to 103 grains without pressure, but no chronograph. I'd guess 3100 fps or about there with 103 grains.
     
  5. jmden

    jmden Well-Known Member

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    Thanks duster and Tyler. Data made more interesting with same man. and lenth barrel. Tyler, it'd be interesting to see what the chrono would show with your barrel and H-50BMG.