Small Arms Firing Regulations for the United States Army and the Organized Militia of the United States - Tapa blanda

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908. Excerpt: ... PART VIII. FIRE DISCIPLINE. CHAPTER 1. MOTION OF BULLETS. 352. When a rifle is discharged the bullet is acted upon by several forces, viz, by the projectile force, by the force of gravity, and by the resistance of the air. The effect of these forces is also modified by other minor forces which influence, often irregularly, the flight of the bullet. THE PROJECTILE FORCE. 353. The explosion of the cartridge gives rise, by the decomposition of the powder, to a large amount of gas, which, being highly elastic, endeavors to occupy a space much greater than that in which the powder was contained, and consequently exerts considerable pressure in every direction. The pressure upon the sides of the barrel only sets up vibrations in the metal; that in the direction of the breech induces the recoil, which in turn depends upon the projectile force and upon the weights of the rifle and bullet; that in the direction of the muzzle imparts motion to the bullet, which motion, during the passage of the bullet through the barrel, experiences resistance from the sides of the grooves, from friction against the surface of the bore, and from resistance of the air. 354. The projectile force continues to act while the bullet is in the barrel, causing it to move with an ever-increasing velocity until it reaches the muzzle. The velocity with which the bullet finally issues from the barrel is called the initial or muzzle velocity, and is measured by the number of feet it would pass over in one second, provided its rate of motion remained unchanged. 355. If, after leaving the muzzle, the bullet were subjected to no other forces, It would continue to move In a straight line, following the direction of the axis of the bore, which is called the line of fire, and with, at all points in i...