Re: Chainguns vs. Gatlings

In message <3903DB7D.71DB4AF4@home.com> Thomas Barclay of the Clan
Barclay writes:
> Some good info in the discussion so far.
> 
> Only, riddle me this - are their chain driven mutli-barrel guns?
>
> If so, then there is a union of the sets Chaingun and Gatling gun.

I think you misunderstand what a "chain gun" is.

A chain gun is a specific sort of (patented and trade-marked)
mechanism in which (if I've understood all the techo-gobledigook
correctly) the breech is directly connected to the chain, which
drags it forward and backward as it is driven around its race.

You really couldn't marry this to the gatling gun principle in
which the breeches of each barrel are spinning around... each
barrel would need a seperate chain drive for its breech, which
would also spin around... probably you *could* do it, but it
would be a very odd and complex system, which rather defeats the
object. You might just as well drive multiple chainguns off the
same motor and leave out all this spinning business.

One of the reasons that gatling guns can have such high rates of
fire is that by having multiple barrels/breeches the ROF is less
constrained by having to wait for the gas pressure in the barrel
to drop before extracting the case from the breech. Conventional
rifles and machineguns need some sort of locking system to stop
the case from extracting while the pressure is high enough to
shred the case as it leaves the breech. This is equally true for
chainguns... if you drove the chain at double speed the timing
might cause not a double ROF but some major stoppage. Since the
required delay is the same limitation as conventional weapons have
a 7.62mm chaingun can easily have the same ROF as any other MG.

To veer this towards sci-fi this problem of gas pressure would
presumably not exist in a "gauss" or railgun, allowing a single-
"barreled" weapon to have a magnificent ROF. OTOH, the physical
mass of a gun barrel would have to be there in the system somehow
to act as a heatsink. Love that thermodynamics.

-- 
David Brewer