Bob, at 11:38 on May 23 1996, you wrote to Bill Grimsley...

BL> If you fire an M16 it leaves the muzzle at Mach-3 (990m/s),

BG> In case you're interested, the fastest commercially available
BG> rifle cartridge is the .220 Swift, with a muzzle velocity of
BG> just over 4000fps... 

BL> 1220m/s; mach-4. The back pressure must be incredible.

The breech can handle it, but the Swift chews out barrels with great speed.

BL> There is a law of diminishing returns. The 5.6mm load is just as large as 
BL> the 7.6mm one.

This is far too involved to go into here, but as a one-time reloader of my
own cartridges, ballistics is a science all on its own.  There are actually
several different types of gunpowder, and it's not so much the volume of
powder used, as its burn rate when ignited which creates the force required
to propel the projectile from the barrel.  Check your library, as it's
interesting stuff.

Regards, Bill
@EOT:

--- MsgedSQ/2 3.30