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Home > Propellants, Firearms, and Ammunition Development > Evolution of Firearms > Rifled Barrels > Projectiles

In addition to other modifications to improve their guns, Pennsylvania gunsmiths introduced the use of tallow-soaked cloth or buckskin patches to wrap around the ball. The ball could be smaller than any internal portion of the barrel; the patch made up the size difference. An undersized ball in a lubricated patch could be easily seated with a standard ramrod. The patch pushed powder fouling from previous shots back down the barrel, leaving the bore cleaner for the next shot. The texture of the tight-fitting patch provided the necessary friction to grip and spin the ball as it sped down the barrel. The patch also ensured that most of the powder gas remained behind the bullet.

In theory, a sphere should travel through air equally well with or without spin stabilization. In practice, as soon as the propellant’s pressure wave acts upon the soft lead ball, it is deformed into a stubby cylinder. In-bore deformation of a projectile by firing pressure is called slugging. By their nature, cylinders require artificial stability; this is provided by the spin imparted by rifling.

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