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Theoretical bullet max velocity?

  1. Dec 14, 2013 #1
    What is the theoretical max velocity for a gunpowder fired bullet that we use today in all guns and artillery? What is the MAIN limiting/deciding factor?

    I'm guessing it would be the gunpowder burn speed/pressure increase right?


    Now what about theoretical max velocity for electrochemical guns? Using electricity to produce plasma/pressure to propel the bullet...

    I had a crazy idea for a electrochemical accelerator but wasn't sure if it was worth pursuing...

    Thanks for any input guys.
     
  2. jcsd
  3. Dec 14, 2013 #2

    CWatters

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  4. Dec 14, 2013 #3
    Thank you for the link. That explains the gunpowder propelled bullets, does it also apply to electrochemical gun as well since in them you are still propelling a gas (plasma) which seems to be one of the limiting factors? Or can plasma accelerate easier then an expanding gas from burning gunpowder?

    No really worried about railguns, I understand those pretty well.
     
  5. Dec 14, 2013 #4

    CWatters

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    Sorry I don't know how the electrochemical guns work.
     
  6. Dec 14, 2013 #5
    Simple, you have the bullet, right behind it you put a small peace of usually aluminum foil, blast the aluminum foil with a huge capacitor, current turns the foil into plasma, plasma pushes the bullet out...
     
  7. Dec 14, 2013 #6

    CWatters

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    Is it the expansion of the aluminium gas plasma that pushes the bullet out or do you use a rail gun coil acting on the plasma to push it out?

    I suspect the former suffers from same limitations as explained in the link (energy needed to accelerate the gas plasma is wasted). Would the latter be very different from other rail gun that act on the bullet directly? Just thinking aloud as I'm no expert.
     
  8. Dec 14, 2013 #7
    I recall reading a post, years ago, by someone in the military weapons business. Apparently, the major limit on projectile velocity is the rifling of the barrel - at some point, the bullet merely strips across them and does not engage the spiral.
     
  9. Dec 14, 2013 #8

    Vanadium 50

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    It's not obvious to me that there is any military advantage to faster projectiles. You still have to launch the thing and there are physical limits to that: that's why you don't see destroyers with battleship-sized guns.
     
  10. Dec 14, 2013 #9
    Yes its the pressure of the plasma that pushes the bullet, no coil there so it sounds like it would be the same limitation as gunpowder. Unless aluminum turns to plasma instantly but then that isn't good either since thats like using explosives to propel a bullet and that does work

    Well faster projectile = more energy. Thats why the military is spending millions of $ to get a reliable railgun onto navy ships with in next 5 years... Velocity equals accuracy and insane range of the weapon. If you can take your enemy our from 100 miles away, you need far less ships on the sea. In military railguns they aren't even worried about using explosive projectiles as the projectile on its own contains so much energy at those high velocities that the explosive isn't even needed.
     
    Last edited: Dec 14, 2013
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