Pauling and his committee were to focus primarily on propellants used for hyper-velocity
guns, meaning weapons that fired projectiles at greater than 3,200 feet per second.
They were concerned with three factors of propellants: explosive power, erosive ability,
The explosive power of a propellant determines the speed at which a projectile leaves
the muzzle of a gun, in turn dictating the range and penetrative ability of the weapon.
The force generated by contemporary propellants largely met the needs of the U.S.
military, but there was concern that new German and Japanese vehicles - tanks, ships,
and planes - would be better armored and therefore resistant to preexisting powders.
Erosiveness was another concern for the committee. A projectile is propelled from
its gun barrel by the combustion of the propellant. Each explosion, a combination
of heat and pressure, puts strain on the barrel by pressing outwards against it, heating
it and stripping particles from its interior. After enough firings, the interior
of the barrel is worn down until it is no longer tight around the projectile. As
result, much of the force from the propellant's detonation escapes around the projectile,
reducing the velocity of the round, thereby decreasing its striking force and range.
What's more, erosion can wear down the rifling of a gun barrel, creating an uneven
spin in the projectile which causes it to bump against the interior of the barrel
as it exits, greatly reducing the weapon's accuracy. In order to combat erosion,
it was necessary for high velocity guns in use in the field to have their barrel liners
changed frequently. Not only was this a time consuming process, but it required gun
crews to transport barrel liners, which could be problematic to move and a drain on
wartime steel reserves. Some propellants, due to a variety of factors including force
and temperature of the explosion, were more erosive than others, something that Pauling's
committee hoped to study in detail.
Finally, the committee was tasked with the analysis and reduction of muzzle flash.
Muzzle flash occurs as the high pressure gases created by the propellant's explosion
exit the barrel, resulting in a bright flare of light. On large guns, like the hyper-velocity
weapons that the ballistics committee researched, muzzle flash can be exceptionally
bright. The extreme brightness tended to be damaging to the eye, especially for gun
crews working at night, and was known to cause retinal scarring and blindness. Even
more troubling, muzzle flash from large guns could be seen from several miles away
and could be used by enemy forces to pinpoint artillery locations, making entrenched
weapons an easy target for enemy assault.