rifling

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The process or operation of cutting spiral grooves in a rifle barrel.
2. n. Grooves cut in a rifle barrel.

Century Dictionary and Cyclopedia

1. n. The act of plundering or pillaging.
2. n. plural The waste from sorting bristles.
3. n. The operation of cutting spiral grooves in the bore of a gun.
4. n. A system or method of spiral grooving in the bore of a rifle. Whatever may be the form of cross-section in the grooves, the modern practice is to make them, for small-arms, extremely shallow; and, though the rectangular form with sharp angles is still retained, the angles are commonly rounded, this being an easier form to keep clean. Henry's system of rifling, used in most military rifles, has seven grooves; and the grooves make one turn in 22 inches. The grooves are broad, rectangular, and very shallow, with rounded angles, the lands being much narrower than the grooves. This is the system used in the Martini-Henry rifle. The system most in vogue in America for match-rifles is that of a uniform spiral, one turn in 18 inches, with very shallow grooves. With shallow grooves, hardened bullets are required; and the method of shallow grooving, with hardened bullets, is now taking the place of deep grooves and soft bullets, which were characteristic of Whitworth's and Henry's system of rifling. In express-rifles the rifling is very shallow with a slow spiral (one turn in 4 feet to one turn in 6 feet); and six is considered the best number of grooves. The so-called “Metford system” of rifling, used in England for fine match-rifles, employs five extremely shallow grooves, each including about 32° of the circumference of the bore, the twist of the spiral increasing toward the muzzle, generally finishing with one turn in 17 inches; but it is part of this system to vary the spiral in different guns according to the character of the powder to be used. In large-bore rifles with shallow circular-arc-bottomed grooves, the grooves are often ten in number, with one turn in 7 feet. A system, still of doubtful expediency, has been introduced, called the non-fouling system. In this method the barrel is rifled in its front half only. Some very fine shooting has been done by guns thus rifled. The Whitworth system of rifling is that of a hexagonal bore with spiral faces. It is still retained for ordnance. The projectiles for such rifles are also hexagonal with twisted sides. The Haddan system of rifling for ordnance consists of three spiral grooves of deep elliptical cross-section, into which fit three wings on the front of the shot or shell. Other shapes of grooves are also used for ordnance.

Wiktionary

1. n. The act or process of making the grooves in a rifled cannon or gun barrel.
2. n. The system of grooves in a rifled gun barrel or cannon. Shunt rifling, rifling for cannon, in which one side of the groove is made deeper than the other, to facilitate loading with shot having projections which enter by the deeper part of the grooves.
3. v. present participle of rifle.

GNU Webster's 1913

1. n. The act or process of making the grooves in a rifled cannon or gun barrel.
2. n. The system of grooves in a rifled gun barrel or cannon.

WordNet 3.0

1. n. the cutting of spiral grooves on the inside of the barrel of a firearm