Which option represents the direction of twist derived from rifling?

• A. Caliber
• B. Dimension of lands
• C. Material of barrel
• D. Direction of twist

Answer: (D)

The main idea is that rifling has a twist direction, which is the way the grooves spiral along the barrel to spin the bullet. This direction—often described as right-handed or left-handed twist—determines the gyroscopic spin imparted to the projectile, helping stabilize it in flight. Forensic analysis uses this twist direction to link bullets or cartridge impressions to a firearm, because the rifling direction leaves characteristic marks that can be matched or differentiated.

Caliber refers to bullet diameter, dimension of lands describes the spacing and width of the rifling lands, and the material of the barrel is about what the barrel is made from. None of these describe how the rifling twists along the barrel, which is why the direction of twist is the correct concept here.