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Bullet Mass vs. Velocity

Discussion in 'General Firearm Discussion' started by Tokarev Czar, Mar 24, 2012.

  1. Tokarev Czar

    Tokarev Czar Arizona New Member

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    I know this is an oldie but a goody. Since kinetic energy increases 4 fold when doubling velocity what is the majic number at which bullet velocity starts to "out weigh" mass...pun intended. Epecially with all the designer rounds, bullet mass vs. velocity deserves a second look. Also, what about pistol cartridges that can reach over 2000 ft per second? (7.62x25mm) Worth another look?

    Interesting article on the subject:

    Tokarev 7.62x25mm vs. m1911 .45 ACP: Velocity or Bullet Mass?
     
  2. Mark W.

    Mark W. Silverton, OR Bronze Supporter Bronze Supporter

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    Where do you get 2000fps for a 7.62 x 25 round? In my reloading manuals MAX loads are running 1700fps in a 4.5" barrel with a 90 gr HP hornady In the Sierra book the MAX load is 1550fps with a 85gr RN
     
  3. MarkAd

    MarkAd Port Orchard Well-Known Member

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    Engineers wrote those specs. Engineers typically limit max loads to 80% of design.
     
  4. fd15k

    fd15k Tigard,OR Well-Known Member

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    I tried shooting IIIA armor plate with 7.62x25, it didn't go through. What kevlar helmets are those then ?
     
  5. Tokarev Czar

    Tokarev Czar Arizona New Member

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    Hello fd15k,
    What kind of ammo did you use? Oh, by the way, it goes through the armor, not the trauma plate (or at least regular ammo), I bet the .223 Timbs would.

    Tokarev Czar
    The Tokarev Nation
     
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  6. mr45auto

    mr45auto Oregon City Member

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    Interesting little article but apparently nobody bothered to notice the .45acp has other loadings than just 230gr ball. Have a looksee at 230gr Winchester Ranger RA45TP for a loading that makes more energy at 100yds than a .40 at the muzzle. I've personally killed deer with the standard pressure RA45T and it's seriously effective. My CZ52 in 7.62x25 was a flat shooter for sure but there is no way I'd consider it more versatile than the .45acp. If you really worship at the altar of lightweight and velocity there are loads as light as 92 grains in .45acp and at 2000fps it's no slow poke.
     
  7. Tokarev Czar

    Tokarev Czar Arizona New Member

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    mr45auto,
    I have seen 68 grain .45 Super Swat magsafes that are 2,200 ft per second. Who makes 92 grain in .45ACP that exceed 2000fps?

    Tokarev Czar
    http://hubpages.com/t/2ef6f0
     
  8. fd15k

    fd15k Tigard,OR Well-Known Member

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    Used surplus FMJ ammo fired from CZ52. I said plate because that's what it was - composite armor plate rated IIIA. I wasn't talking about vest/trauma plate :)

    4 shots are visible: one .40S&W, one 9mm Luger, two 7.62x25.

    2012-04-09_10-44-41_856.jpg
    2012-04-09_10-44-53_948.jpg
     
  9. fd15k

    fd15k Tigard,OR Well-Known Member

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    Are you looking at barrels of equal length though ? Say RA45TP gives you 990ft/s out of 5 inch barrel. That is 500ft-lbs.
    Now to compare let's take Double-Tap 200gr S&W. Launched from a 3.5" barrel it gets to 990fp/s, getting 435 ft-lbs of energy.
    But it is 1100fps from a 4.5" barrel, getting some 538 ft-lbs.
     
  10. Swedish K

    Swedish K SW Washington Moderator Staff Member

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    Mark - I believe the 2100(+)fps was in reference to a 52 grain projectile, not the far more common 90gr or 85gr bullets.

    as for the 7.62x25 vs .45acp argument - there are far too many variables to be considered and one thing I noticed in the article was that they never out and out stated a comparison of cartridge X vs cartridge Y. They refer to .45 in 230 grain which is the most common ball ammo but when talking about the 7.62x25 they are not consistent - some times its "standard" ammo and sometimes its specialty 52gr pumping out over 2100fps. I'm not saying that the arguments were false but it certainly wasn't apples to apples on a level playing field. I would like to see a comparison that included all of the information - if we are talking standard issue ball for .45 then it should be standard issue ball for the 7.62x25 as well. Also include ballistic gel test data (with and without denim) and to be fair show the initial crush cavity data, the permanent crush cavity data, and the penetration data. This might give us a more reasonable comparison instead of just foot pounds of energy (kinetic), which can be misleading.

    As always, shot placement is more important than the rest of the comparison.
     
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  11. mr45auto

    mr45auto Oregon City Member

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    Just pulled up two from the Winchester Ranger line. Wasnt really worried about going further but .45 Super can be safely run through a resprung 45acp pistol. If you're looking for oomph Super level loadings definitely have it. The .45 Super is listed at DoubleTap as .450SMC to avoid conflict with Ace Custom ( If I recall that correctly anyhow )

    the 92 grain load is the old Magsafe Agent. I still have a few around. I chronographed it well north of 2K out of my 5" Govt model.

    Dont get me wrong I like the 7.62x25 it's an impressive little cartridge but versatility favors the larger round. The little 7.62 is the undisputed penetrator though.
     
  12. fd15k

    fd15k Tigard,OR Well-Known Member

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    Haha, I have a G20 for some extra juice : 200gr going at 1250fp/s reaches almost 700ft-lbs :rolleyes: