Re: Metal Storm (Long-ish)

bbrush@unlnotes.unl.edu wrote:

> I didn't want to get into hard (or even soft) numbers, but IIRC the
Phalanx
> had an ammo capacity of something like 250-300 rounds.  That's only
about
> 25-30 metalstorm barrels.  Let's say we mount 10 metalstorm barrels in
a
> frame.  That's 100 rounds, and probably roughly 30 pounds (or so).
> [According to a previous post the barrels are stronger and lighter
than
> regular firearm barrels, at the expense of durability.]  You'd need 3
of
> them to replicate a Phalanx  so that's 90 pounds of consumables. 
Reload
> time would be maybe 2 minutes under combat conditions, and any swabbie
> could schlep a 30 pound rack one-handed.  You could probably even
double
> that to 60 pounds and it still wouldn't be unmanageable.  And remember
> we're talking about automated point defense where volume of fire is
more
> important than pinpoint accuracy not to mention the fact that it's not
> going to be used continually.

Where do we start?
A google search of phalanx and M61 cannon sites puts the capacity at
900-1000 rounds, and the weight
of each round is 0.56 pounds.  This puts the mass of the weight of a
unit load at 500 to 560 pounds.
Now we need 90 to 100 metalstorm barrels.  The cartridge is 6.6 inches
long, so a metal storm barrel
must be at least five and a half feet long to hold ten.  If we assume
that half the length and one
tenth the weight of a vulcan is its six barrels (the estimate is absurd,
but favors metalstorm) and
the length containing the projectiles and propellant is no heavier than
ten cartridges (still absurd),
each barrel is 9'6" long and weighs 9 pounds [an M61 cannon, w/o ammo is
6'1.4" and 252 pounds].  The
real killer here is not the weight, but the length.  The barrels have to
stop wobbling before they can
fire, so they either have to be stiff (read: heavy), or they are in a
rigid mounting.  While the
barrels are no heavier with a rigid mounting, replacing them is more
work (or more automatics which
make the mounting even heavier [one of the goals is to save weight?]).

Against an exocet [the missile that blew a great smoking hole in the
Stark] being six inches off of
the bulls' eye is to completely miss the target.  This is where the
"low" rate of fire of the phalanx
is not a liability.  The very expensive and sophisticated radar is
connected to a fast enough computer
that drives a sufficiently rigid mount that small corrections can be
applied between each shot fired.
The problem with phalanx is not that it fails to hit (assuming that it
is switched on and running),
but that a 20mm round may not be enough to kill the missile.  Pinpoint
accuracy really is important,
or ammunition consumption goes up and it is a patently obvious fact that
on a per round basis,
metalstorm requires more volume than a more conventional mount.

Metalstorm is very much like the fax machine was when it was first
invented (~1850), an interesting
device that provided a service that noone really needed.