Presence of spiral grooves in the barrel of weapon is referred to as -

The synopsis of forensic medicine & toxicology ; Dr k.s narayan reddy ; 28th edition ; pg.no 123 & 124 The bore is cut internally with number of shallow ,spiral " grooves" varying from two to more than twenty ,the most common being six ,which run parallel to each other but twisted spirally ,from breech to muzzle . The groove are called rifling and the projecting ridges between these grooves are called "lands".