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Thread: O yee enlightened ones

  1. #1

    Question O yee enlightened ones

    I was pondering this today. Most persons of unquestionable character, claim that thru extensive research, the .458 Win Mag 400gr bulllets are at their best if velocities are in the 23-2400 fps. So, my question is this: why is the most recommended velocity for the same bullets in the 45-70 around 12-1600fps? What am I missing?
    If you like getting kicked by a mule...then you'll "love" shooting my .458.

  2. #2
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    This is an easy one. The maximum velocity with 458 Win and 400 grain bullets is 2300-2400 fps, that's as fast as you can get them. And a 400 grain bullet in the 45-70 is going to be about 1950 fps and not exceed the strength the lever guns chambered for it.

    I think the 458 Win Mag is at it's best with 450 grain bullets at about 2200 fps. The 45-70 must be loaded to lower pressures and depending on the application and type of rifle can be used effectively with 350 to 450 grain jacketed or up to 500 grains with cast bullets with velocities varying from 1300 to 2000 fps.
    Is there nothing so sacred on this earth that you aren't willing to kill or die for?



  3. #3

    Talking OK Murphy

    But: I understand the strength limitations of the 45-70 rifles dictating the ultimate velocity in the ranges you mentioned...but... I've read numerous statements that a slower bullet (not max) from a 45-70 will out penetrate equal bullets out of a 458 mag loaded to higher velocities. I know that bullets loaded to extreme velocities might have less penetration because of the more violent expansion, but that isn't the case they're referring to.
    If you like getting kicked by a mule...then you'll "love" shooting my .458.

  4. #4

    Default velocity vs penetration

    I'm not sure what you are referring to when you say "That isn't the case they mention" or what statements you have read or even if they are to be taken at face value, but yes, sometimes an "equal" bullet at slower speeds can penetrate further, but not necessarily. If you shoot a rapidly expanding bullet meant for a 45-70 in a .458 Win, the rapid expansion caused by the thinner jacket can detract from the projectiles penetrating abilities. If you use a good solid of 500 grain weight in a .458 at say 2100 fps, it will probably penetrate better then the same bullet at 45-70 velocities. The same bullet pushed to higher but still reasonable velocities will still penetrate well. If you shot the same bullet at the same velocity in a .458 Win AND a 45-70 at the same velocity, there is no reason why it wouldn't penetrate exactly the same. If you shoot a LBT type Wide Flat Nose bullet in a 45-70 at 1900 fps and the same in a .458 at say 2300 fps, I'd be surprised if you didn't get better penetration. There are a lot of variables and the bullets commonly used in the .458 Win are not the same as for 45-70, nor should they be.

  5. #5
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    Oh, OK, I got a little off in left field there.

    45-70 velocities and the bullets made for it determine where and when and how much each expands. For hard cast bullets a velocity of around 1400 fps will give the best penetration. This because energy and momentum are high enough to penetrate but not so high as to cause the bullet to expand, deform or crumble, (given proper temper) any of these three will reduce penetration. Expansion or deformation may make a large wound cavity but the question was penetration.

    The same with jacketed soft point bullets. The more it expands the less it penetrates. Bullets made to expand at 1600 fps will expand some at 1300 fps and a lot at 1900 fps. Penetration will be reduced proportionally. Bullets made for the 458 Win Mag will expand less at 45-70 velocities and some not at all, such as the 500 grain due to the tougher construction and it by necessity will be driven at slower velocity.

    Back to the effectiveness of bullets in the 2400 fps range. There is some significantly greater wounding ability by bullets when driven to the range of 2250 to 2400 fps. An obviously greater effect in killing power and it is agreed on by most any who have use both slower and faster bullets. The great 416 Rigby and the 375 H&H, two of the first medium bore calibers to exceed this power threshold, showed much greater killing power than their older slower black powder cousins. The 7x57 Mauser and the 30-06 Springfield gave results on a par with the best of the black powder big bores with much slower and heavier bullets.

    The jump to smokeless and cordite propellants gave velocity above the slower "puncture wound" velocity of the BP era (about 1500 fps) by pushing velocity above 2000 fps. Then the next hurdle and obvious step up in killing power was to 2400 fps.

    This equation is best seen by studying Taylors famous TKO tables. Increasing bore size, bullet weight or velocity, any one, will up the effective ness of any bullets. Velocity must be governed because it can also destroy the bullet which is the instrument to cause wounding. It must remain intact or no amount of bore size or bullet weight can do much.

    At about 2000 fps there is some impact destruction,greater than just the bullet path, then more at about 2400 then 2800 fps, and so on. There seem to be definable steps.
    Is there nothing so sacred on this earth that you aren't willing to kill or die for?



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