The Scientific War Work of Linus C. Pauling Narrative  
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Hyper-Velocity Guns
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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, and flash.

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.

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See Also: "Mechanism of Gun Erosion." June 30, 1942. 

Click images to enlarge 

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Conceptual sketches of German Radio-Controlled Rocket-Driven Flak, "Rheintochter" R1 and R3. approx. 1945.

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"Hypervelocity Guns." June 30, 1942.

"This Committee recommends that a program of experimental study of the relative erosive powers of propellants with special reference to hyper-velocity guns be begun immediately by Section A of Division A of the NDRC, with the advice and cooperation of the Army and Navy."

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