noun, noun or participle which takes 'suru'
rifling (of a gun barrel); cutting spiral grooves
Technical term used in firearms engineering. The 'making lines' gloss refers to the act of cutting the spiral grooves inside a barrel.
銃身に施条を施すことで弾丸に回転が与えられる。
By rifling the barrel, spin is imparted to the bullet.
この工場
This factory performs precision rifling work.