COMPRESSION PROJECTILE n.
A projectile constructed so as to take the grooves of a rifle by means of a soft copper band firmly attached near its base or, formerly, by means of an envelope of soft metal. In small arms the modern projectile, having a soft core and harder jacket, is subjected to compression throughout the entire cylindrical part.…
CORRUGATE v.
To form or shape into wrinkles or folds, or alternate ridges and grooves, as by drawing, contraction, pressure, bending, or otherwise; to wrinkle; to purse up; as, to corrugate plates of iron; to corrugate the forehead. Corrugated iron, sheet iron bent into a series of alternate ridges and grooves in parallel lines, gi…