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  1. #11
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    Nov 2014
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    Default Re: Monolithic Expanding Bullets, Weight and Velocity.

    Quote Originally Posted by Messor View Post
    People get confused on the subject because there is a whole heap of variables that comes into play, but when you sit and think about it logically it’s really quite simple.

    Now when people started making mono’s, they of course ran into the trouble of firstly trying to stabilize them, but more importantly getting the composition and nose cavity design correct in order to get optimal expansion. To calculate stability is the easiest thing in the world, so that should not be a factor at all, but copper is hard, I would venture a guess that by far the single biggest reason people advised to drop a bullet weight in copper is to get the speed up, so that the bullets open reliably.

    This unfortunately stuck with many people, but in reality it’s only applicable when you deal with specific bullets. To say one 165gr mono bullet won’t open up because another brand did not is incorrect, bullets all differ and act differently under certain impact velocities.

    You can go light with mono’s, because of their penetration potential, but forget not the heavier a bullet the more material, the more material the greater the potential of the nose cavity size, aka how big the bullet can open up when it expands, and that governs how big a permanent wound cavity can be created. If this was not so then we would shoot solids, but we don’t, we need that big frontal area.
    I think one also needs to consider that with each bullet weight and diameter, the way the bullet expands differs, so manufacturers have to try to make incremental changes to each type to get the same expansion characters across the range. And that gets tricky!

  2. #12
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    Dec 2009
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    Vereeniging
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    Default Re: Monolithic Expanding Bullets, Weight and Velocity.

    Story - PMP loaded Barnes X bullets in a premium line that was punted as the best ammo in Africa. Their experiment failed because they loaded the traditional weights in a lot of calibres. The bullets tumbled and poor accuracy was found. They later sold some of the bullets and I tried the 175BX in my 7x64. We shot one kudu cow with it and the bullet tumbled. What a mess - the whole carcass was blood shot on the entrance side. I have never seen something similar before.

    To make sure that the 1 in 12 twist 308's could effectively use his bullets, Gerard Schultz made them with a weight of 130gr. This ensured a stable bullet that killed effectively and had ample penetration. Nobody complained and brought home the biltong. Many reloaders do not have time to experiment with different weights and the lighter bullets worked well - why fiddle with a success story.

    The above is my reply to TStone's remark about a 150gr mono in the 308. Time has moved on from where GS Custom started and their advice of those days. The 150's would need a 1 in 10 twist and a lot of 308's have been supplied that twist. The 130's however would be the safer bet to advise a re-loader if unsure of twist and he can then hunt with the knowledge that the bullet will not fail at normal ranges.

  3. #13
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    Dec 2010
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    On the Gariep
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    3,949

    Default Re: Monolithic Expanding Bullets, Weight and Velocity.

    In my few dealings with Gerrie Schultz he made it very clear that he was right and everyone who differed from him was wrong even if they had practical results that backed up their opinions. If told that one of his bullets behaved in a manner different from what it was advertised to do, he simply put the blame on the user. For this reason I find it hard to take any advice from him very seriously.

    Peregrine bullets, as an example, list the appropriate minimum twist per bullet weight. Their recommendations does differ quite a bit from those of GS Customs. What also differ is their reaction to negative feedback from people using their bullets. They actually pay attention to customer feedback and do something about it. Instead of insisting that their bullet is perfect and the customer is incompetent. As an example, they changed their VRG-4 bullet line to the VLR-4 which expands much more readily at lower impact velocities(longer ranges).

    I am not suggesting that everyone start using 180gr mono-metal bullets in their .308 Winchester's but I have seen 165 - 180gr mono-metal bullets (both Peregrine and Barnes TSX) perform very well on game in this caliber. In a 1 in 14" twist .308 a 130gr bullet is a great choice but for a 1 in 12 twist I really believe that a hunter will be better served with a 150 grainer.

    A 175gr mono-metal bullet in a 7mm is an extreme example it will probably be equivalent to a 220gr .308" mono-metal bullet, I do not know if even a 1 in 8" twist will stabilize it properly.

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