The Chemistry of Powder and Explosives - Sciencemadness Dot Org

324 SMOKELESS POWDER
the number of mols of gas is actually increased while the temperature
is lowered;
(3) by incorporating in the powder a cool explosive, such as
ammonium nitrate, guanidine nitrate, or nitroguanidine, which
explodes or burns with the production of gas notably cooler than
the gas from the combustion of ordinary smokeless powder; and
(4) by contriving the ignition of the powder, the acceleration
of its burning rate, and the design of the gun itself, any or all
these factors, in such fashion that the projectile takes up energy
from the powder gas more quickly and more effectively than is
ordinarily the case, and thereby lowers the temperature of the
gas to a point where the flash is extinguished.
The first of these methods is applicable to all calibers; the second
and the third are successful only with calibers of less than 6
inches; the fourth has not yet been sufficiently studied and
exploited. It is true, however, that an improved igniter, with the
same gun and with the same powder, may determine the difference
between a flash and a flashlcss discharge.
The use of salts to produce flashlessness appears to derive from
an early observation of Dautnche that a small amount of black
powder, added to the smokeless powder charge of small-arms
ammunition, makes the discharge flashless. During the first World
War the French regularly loaded a part of their machine gun
ammunition with a propellant consisting of 9 parts of smokeless
powder and 1 of black powder.
The Germans in their cannon used anti-flash bags or Vorlage,
loaded at the base of the projectiles, between the projectiles and
the propelling charges. These consisted of two perforated discs of
artificial silk or cotton cloth sewed together in the form of
doughnut-shaped bags. The bags were rilled with coarsely pulverized
potassium chloride. The artillerymen were not informed
of the nature of the contents of the bags but were advised against
using any whose contents had hardened to a solid cake, and were
instructed in their tactical use as follows.
In firing with Vorlage, there is produced a red fire [a red
glow] at the muzzle and in front of the piece. The smoke is
colored red [by the glow]. This light however gives no reflection
in the heavens. In fact it is visible and appreciable
at a distance only if the piece is placed in such a way that