Large vs. Small Rounds

Adrian Hurt Writes:
>Actually, I believe it is energy which kills.  5.56mm bullets come from
>smaller cartridges than 7.62mm ones, and so have less kinetic energy when
>they leave the barrel.  Being lighter, they are more affected by air
>resistance than 7.62mm bullets, so they lose more energy on the way to
>the target, which is why 5.56mm rifles have shorter ranges than 7.62mm
>rifles.  (This is all inexpert opinion based on what I've read when this
>sort of discussion comes up on the newsgroup sci.military, by the way.)

I'll agree with you on the fact that it is energy that kills, but kinetic
energy is calculated by 1/2Mass*Velocity^2.  Therefore, I believe that
the greater velocity of the smaller rounds more than makes up for their
lesser mass.  I also agree that the heavier rounds often have greater
maximum ranges, but maximum effective range is what concerns me.  A
5.56mm bullet fired from a M-16A2 has a maximum effective range of
540 meters, if I recall correctly.  It is somewhere around 800 meters
when firing at a grouped target, on burst setting.  Those ranges are,
in my experience, pretty long as firefights go.  I'm not talking
snipers here either, as they tend to use larger rounds that also happen
to have high muzzle velocity.  Marine snipers use the Remington 700,
which is a 30-06, I believe.  (They also engage targets at 1000 meters!)

>In fact, in the days of Striker, in which a gauss rifle's penetration was
>not that much better than a 9mm ACR's, I tended to prefer the ACR.  Firing
>DS ammo, its penetration was 6 to the gauss rifle's 7, which wasn't too bad.
>And the ACR, being lower tech, could get ammo from more planets than the
>gauss rifle - if the worst came to the worst, it could fire ordinary slug
>ammo, which had a much lower penetration than DS but a much better penetration
>than an empty gauss rifle.  Slug ammo, being even lower tech, was readily
>available on any world civilised enough to be of interest and uncivilised
>enough to let characters wave ACR's around. :-)

This helps prove my point.  Note that the ACR is firing DS (Discarding
Sabot) ammunition.  Discarding Sabot is a round that after it leaves
the muzzle of the weapon, drops a jacket which surrounds a _smaller_
diameter penetrator which then has a greater velocity.  Therefore, the
round has a greater penetration (higher kinetic energy).  However,
the remainder of your argument is irrefutable.  An ACR firing ball
ammunition is far better than an empty Gauss rifle.  I am a great
believer in peace through superior firepower! :-)

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Lee Eilers  [email removed]

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^Z