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5000 fps...and if so...why?

Discussion in 'General Gun Discussions' started by Redlg155, Apr 24, 2012.

  1. Redlg155

    Redlg155 Well-Known Member

    I was looking through my newest Lee reloading manual and noticed that I did not see a load over 5000 fps or so. The fastest listed is a 20gr bullet at approx 4600 fps.

    Does anyone make a heavier, lets say 55 grain bullet at 5000 fps, and if so, are there any practical uses?

    What's theoretical or proven speed limit before bullets explode in flight?
    Last edited: Apr 24, 2012
  2. igousigloo

    igousigloo Well-Known Member

    I think you just found it.
  3. rcmodel

    rcmodel Member in memoriam

    It's not the bullets that limit the speed.

    It's the burn rate and expansion ratio of smokeless powder.

    The fastest you can shove a projectile of any weight of any construction, is limited by how fast expanding powder gas can push it at safe pressure limits.

    5,000 is about it with known smokeless powders we have available to us.

  4. 45_auto

    45_auto Well-Known Member

  5. rcmodel

    rcmodel Member in memoriam

    But like I said, smokeless powder available to manufactures and handloaders is the limiting factor, not the bullets.

    Rail guns and particle accelerators can shoot very small things even faster.
    But they use electrons, not smokeless powder.

  6. General Geoff

    General Geoff Well-Known Member

    I've always thought a tiny amount of high explosive such as trinitrotoluene would make for a superb propellant in a shoulder fired small arm, in order to propel a projectile far faster than smokeless powder allows. Unfortunately the pressures involved would require much sturdier construction than is typically found in modern small arms.
  7. 56hawk

    56hawk Well-Known Member

    QuickLoad predicts I can get around 5000 fps by shooting 97 grain aluminum bullets out of my 460 Weatherby. I'm really tempted to buy some and give it a try.

    Here is a link to the bullets: http://lehighbullets.com/products.asp?cat=32
  8. MachIVshooter

    MachIVshooter Well-Known Member

    Smokless propellants expand at a maximum rate of about 6,000 FPS. Of course, you have to account for friction, so the limit on small arms bullet speed using smokeless propellants is a bit slower, around 5,200-5,300 FPS.

    This is why modern artillery is smoothbore; The 120mm sabot KE penetrator rounds like the KEW-A1 are cookin at about 5,700 FPS.

    It takes explosives or electromagnetic propulsion to go faster. Electromagnetic railguns can hit 35k FPS last time I looked, probably more by now.
  9. Jim Watson

    Jim Watson Well-Known Member

    "I've always thought a tiny amount of high explosive such as trinitrotoluene"

    That's been tried with mercury fulminate, nitrocellulose, and nitroglycerine. Those folks soon found that you do not want a shock wave as produced by a true explosive. Even a little of it.

    The propellant for the caseless H&K G11 is/was allegedly a denatured explosive rather than a conventional propellant but the key word is denatured. It had explosive chemistry but had been toned down to deflagrate instead of explode.
  10. fireman 9731

    fireman 9731 Well-Known Member

    Lehigh Bullets makes some amazing stuff....
  11. 45_auto

    45_auto Well-Known Member

    Did you bother to read the article? They do discuss rail guns early in the article, but the one that is the one under discussion uses "a charge of burning powder" to drive the first stage up to about 150,000 PSI. I doubt that it is black powder. Any handloader with sufficient resources (maybe Bill Gates?) could build the same type of staged compression gun to get extremely high velocities, it's a simple pressure vessel. The secret to it is the way they apply the impulse to the projectile.

    From http://www.nytimes.com/1994/03/22/science/fastest-gun-on-earth-goals-go-beyond-planet.html

    Last edited: Apr 25, 2012
  12. Walkalong

    Walkalong Moderator

    His point remains valid to the OPs question.
  13. gym

    gym member

    Talk about fast, the Air force and Navy, have a 12,000,00 mph hyper engine jet, it flies 20 times the speed of sound, NY to LA in 12 minutes. Problem is they keep blowing up, I think they lost 2 so far, what a weapon system that is when they get it right. They said that the paint peeled off the wings.
  14. Ryanxia

    Ryanxia Well-Known Member

    Dam I have to take a better look at my new Lyman reloading book. That's a screamin velocity!
  15. brickeyee

    brickeyee Well-Known Member

    "but the one that is the one under discussion uses "a charge of burning powder" to drive the first stage up to about 150,000 PSI. "

    You mean the ny times has finally discovered what a light gas gun is?

    The problem is that they are not all that useful.

    We have used them for many years to simulate objects impacting satellites.
  16. 45_auto

    45_auto Well-Known Member

    The article is from 1994 .....

    But they've probably forgotten all about it by now!
  17. Blanco

    Blanco Well-Known Member

    Didn't the old Remington .17 get real close to 5k?
    My grandad used a .17 Remi bolt gun for turkey .... Just aim for the head. It usually vaporized it.
  18. alsaqr

    alsaqr Well-Known Member

  19. ldsgeek

    ldsgeek Well-Known Member

    Not the paint but the actual skin of the craft. Bernoulli really messed up that design for them.
  20. Jim Watson

    Jim Watson Well-Known Member

    As Jerry P said of the test, it just goes to show why the ramjet-rocket ground to orbit ship is not a good idea. You do not want to go hypersonic in atmosphere very much.

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