From: earl@cco.caltech.edu (Earl A. Hubbell)
Newsgroups: rec.games.frp.misc
Subject: Re: Explosive rounds
Date: 12 Nov 1992 09:29:03 GMT
Organization: California Institute of Technology, Pasadena
NNTP-Posting-Host: alumni.caltech.edu

acgetche@taco.engr.ucdavis.edu (Adam) writes:

>	Awhile ago I posted an article on special ammunition.  I included
>explosive rounds (revamped in SRun rules), but the net.consensus I got
>was that explosives provide too little energy to do more for bullets
>than fracture the case, making them in effect, super hollowpoints.
>	Thanks to kind sir Marvin Bell, I have done a little research.
>This is what I have come up with:

>	Cyclonite, or hexogen, has a specific energy of 1394 kJ/kg.  Octogen
>870 kJ/kg.  If one consideres a 1 gram bullet fired at 1000 meters per second
>(approximately equivalent to an M-16 round) the kinetic energy is .5*m*v^2.

>	.5*(.001kg)*(1000meters/second)^2 = 500 kg-m^2/sec^2 = 500 Joules.

>	If the bullets mass were composed of hexogen, that 1 gram would 
>liberate 1.394 kJ or 1394 joules, roughly twice the KE of the round.  An
>explosive bullet would therefore liberate more than *three* times the 
>energy that a normal bullet would (the kinetic energy of the exploding
>bullet would still be present in the center of mass).

	Right - so for equal energy for the same volume, we increase the
bullet velocity to 1732 m/sec, or increase the bullet mass to 3 grams
(since even >steel< is 3x as dense as current high explosive).  Since
the topic was 'future weapons', it seems easier to optimize the .5*m*v^2
term (hence the military interest in railguns, light gas propulsion,
kinetic energy tank-killers), than to make stable, energy rich, dense
explosives (which I bet is being researched also...).
	Note that the difference between 'high' and 'low' explosives
is mainly the detonation velocity rather than the energy content.  It's
the pressure spike that increases the damage done (hence the effectiveness
of fuel-air explosives compared to a puddle of fuel).

>	Therefore, even considering things like detonators, stabilizing
>bases, and so forth, it would seem HE rounds would be *much* more damaging
>than any kind of hollowpoint round (which is just an effective way of
>dumping all the KE into the target).

	Explosives only really make sense for low-velocity projectiles,
or when (for whatever reason) you want to spread damage over an area.  So
they find applications in mines, flak, grenades...(self-forged rounds,
skeet mines, demolitions, strange implosion devices of all sorts...)
(most current weapons use relatively low-velocity projectiles, so yes,
explosives would increase damage for current weaponry - on the other
hand, current explosives have problems that make them undesirable for
use in said weaponry...)

>|Adam Getchell |Surgery-Radiation Oncology    GETCHELL@radonc.ucdmc.ucdavis.edu|
>| acgetchell   |ez000270@chip.ucdavis.edu        acgetche@taco.engr.ucdavis.edu|


-- 
'You can tell I'm educated/I studied at the Sorbonne *earl@tybalt.caltech.edu
Doctorate in Mathematics/I could have been a Don     *Earl Hubbell
I can program computers/Choose the perfect Time      *Opinions solely mine.
If you've got the inclination/I've got the Crime" -Opportunities, Pet Shop Boys