Which statement about the M2 rifling is true?

• A. Eight lands and grooves; right-hand twist, one turn in fifteen inches
• B. Six lands and grooves; left-hand twist, one turn in fifteen inches
• C. Eight lands and grooves; left-hand twist, one turn in twenty inches
• D. Nine lands and grooves; right-hand twist, one turn in fifteen inches

Answer: (A)

Understanding rifle rifling and how it stabilizes a bullet is key. The M2 machine gun uses eight lands and grooves in its rifling, which means eight raised ridges and eight corresponding grooves along the bore. It has a right-hand twist, so the bullet spins clockwise as it leaves the barrel, and the twist rate is one turn in fifteen inches (1:15). This specific combination is chosen to reliably stabilize the large, high‑velocity .50 BMG projectile used by the M2, providing consistent accuracy at long ranges. Other descriptions would not fit because they change the number of lands and grooves, flip the twist direction, or use a different twist rate (for example, 1:20), none of which match the M2’s actual rifling.