230 grain Berger Expansion Test Planned

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by mt_archer, Oct 9, 2012.

  1. mt_archer

    mt_archer Well-Known Member

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    I love shooting the .308 230 grain Berger bullets, but have concerns about just how far I can hunt with them so that they have expansion velocity, expecially because I run them through a pointing die. I plan to test them at low velocity out of a 308. Quickload has given me a good starting point on getting velocity between 1750 and 2200 at the muzzle. Load density with Varget at low end is 75%, adjusting for lenght of bullet seated slightly longer than standard, putting them .025" off lands in Steyr scout (1:10 twist, 19" barrel). I am starting with virgin RP brass and CCI BR primers.

    I have brass ready, and an assortment of 230's that are pointed and straight out of the box. I also uniformed the meplat on 5 of them with a meplat trimmer, which will open up the hole at the tip ever so slightly (I cannot reliably measure it with calipers).

    The plan is to chronograph a couple rounds, and test the same load in an expansion medium at close range (hence the use of the 308, not one of my long range rigs, trying to hit the medium properly at 1200-1500 yards).

    Before I get out to the range with this set up, I am soliciting advice.

    1. Do any of you see any risk of detonation fires or other harmful events if I keep my powder density at the estimated 75% or more?

    2. Will the lower rotation rate have any effect on the bullet when it hits? That is, when a bullet leaves a 300 RUM at 3100 fps, it has more rpm's than when it leaves a 308 with same twist at 2000 fps +-. I do not want to have invalid results.

    3. Any suggestions on media to shoot that I can get in bulk, transport, and clean up, that also allows me to test the bullet actions?
    --I don't have enough milk jugs, or any ballistic gelatin.
    --I am considering getting a bunch of boxes, filling them with newspaper, and then wetting them down. But that sure sounds messy when I did through the wet paper and have to haul it back to town to throw away.
    --I have an infinite supply of extremely fine blow sand (I live on a hill made of it). I thought that if I filled a 5 gallon bucket with a 50/50 mix of sand and water (mud), it would approximate flesh. It would also be easier to dump out and leave at the range.
    --whatever I choose, I may need a dozen or more, to check different impact velocities.

    4. If I use anything but a long box of paper, I expect that the bullet will likely pass through multiple water jugs or the 5 gallon bucket. Especially if it does not expand or fragment. Any thoughts on a "bullet trap" to put behind the medium? My range is on the grassy prairie, so I have no hill or dirt bank to catch the bullets for about 2500 yards. Even then, it is a grassy hill, not condusive to finding spent bullets.
     
  2. Broz

    Broz Well-Known Member

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    All I can tell you is they expanded well in a mule deer buck at 891 yards fired from a 300 win and a MV of 2775 fps.

    Jeff
     

  3. mt_archer

    mt_archer Well-Known Member

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    What was your residual velocity? Should have been right at the 1800 fps mark, depending on atmosphere (if my quick check is right)? Do you use pointing die or meplat trimmer?
     
  4. Broz

    Broz Well-Known Member

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    Don't have the impact velocity at hand right now. For the 891 buck elevation was about 6000 ft. We load them right out of the box so far. But I may be looking into a MCR metplat device in the future.

    We also took a few elk with them at the 400 to 550 distance with the same rifle and antelope at 300 a few at 600 and one at 750. Never seen anything I didn't like from this bullet.

    I think Bob Beck and Eric stecker has taken quite a few animals with the 230's too.

    Jeff
     
  5. Tumbleweed

    Tumbleweed Well-Known Member

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    Are you using the 230 OTM's or the 230 Target versions? There's a differnce in B/C's and I believe metplant diameters too. The bullet that Bob Beck has used to take many game animals at various ranges is the 230 Target version with the higher B/C.
     
  6. Broz

    Broz Well-Known Member

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    I am using the OTM's

    Jeff
     
  7. mt_archer

    mt_archer Well-Known Member

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    Failure. At 1975 fps muzzle I could not stabilize 230s.