Berger 215 in 300 win mag, compressed?

Discussion in 'Reloading' started by livetohunt, Mar 13, 2018.


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  1. livetohunt

    livetohunt Well-Known Member LRH Team Member

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    Feb 16, 2017
    I did some reloading last night for load development in my factory model 700 in 300 win mag using Berger 215s and H1000.

    I started at 72 grains and decided to test at .04” off to begin with. I did 1 grain increments up to 77 grains.

    At 73 grains I could here the powder just barely crunching. By the time I hit 77 it was really packing in there and the bullet seating depth was changing due to the compression. I’m using new Sig Sauer brass that I sized and neck turned.

    I’ve never encountered a compressed load before, is what I’m seeing normal? I figure my OAL is probably quite a bit shorter than custom throats but I’m at 3.55” OAL. Am I running out of case capacity because I have to seat the bullet so far in?
     
  2. MagnumManiac

    MagnumManiac Well-Known Member

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    Feb 25, 2008
    Compressed loads only cause problems when they are so compressed that it forces the bullet back out.
    There are 2 ways to make more room for the bullet, either seat the bullet OUT further and single load it, this is what I do for comp guns, or use a technique of powder filling that settles the powder deeper into the case.
    I have used long (24”) drop tubes, sometimes more trouble than they’re worth, or another (better/easier) technique. Using your powder pan and a funnel, you can ‘swirl’ the powder into the case by holding the pan at an angle to the funnel and continuously pour the powder so that it swirls, like a tornado, into the case. At NO TIME should the powder bunch up in the funnel, it should spin into the case.
    A little trial & era is needed to get it right, but once you do, you will see a significant height difference in the powder in the case against one ‘as dumped’ from the pan/measure and, one swirled into the case.
    Yes, it slows down the charging process, but is worth it, I have lowered ES/SD numbers from doing this alone with compressed charges, as the ‘packing scheme’ of the case becomes very uniform.
    Hope this works for you.

    BTW, your throat is normal, and yes, you are taking up powder space with a bulky powder. I use Retumbo and have to load with the above technique or the bullets back out overnight. I load above 3.65” with the 215gr Berger for my rifle.

    Cheers.
    ;)
     
  3. livetohunt

    livetohunt Well-Known Member LRH Team Member

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    Feb 16, 2017
    Ok well that makes me feel more comfortable about what I was doing. I will re-measure and see if any of them pushed the bullets out at all.
     
  4. Alaska2006

    Alaska2006 Well-Known Member

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    Oct 25, 2015
    I would be careful with that load. I shoot a ton of H1000 and Berger 215s but my rifle is throated for loooong seating. 77.0 gr should be safe but is pushing the upper limit. Just not sure how they will react being compressed. I run 77.5 gr to save on brass. I've ran 78.5 gr but only get about 2-3 reloads on good brass so I backed it down a bit. These are not compressed; in fact I can go to 79 gr before it starts to compress.
    I would be careful, if your out on the lands she may build some wild pressures.
     
  5. Lonewolf74

    Lonewolf74 Well-Known Member

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    May 12, 2016
    Besides doing what's mentioned above I would fire 20 or so cases to fire form the brass. Most likely because of the belted case design and how they're first head spaced off the belt your base to shoulder measurement will likely grow .010-.015. From hear only bump the shoulder back .002 or so and you'll have increased case capacity.