Which unit best describes twist rate?

• A. Inches per turn
• B. Degrees per inch
• C. Turns per inch
• D. Inches per second

Answer: (A)

Twist rate is described by how far the bore travels for one complete twist of the rifling, so the standard unit is inches per turn. This directly expresses distance per rotation and matches how rifles are specified, making it the most intuitive and widely used description. Degrees per inch would be an angular measure per length and isn’t the conventional way to state twist, requiring extra conversion to compare with standard specs. Turns per inch is the reciprocal of inches per turn, which can be confusing when matching official data. Inches per second measures velocity, not rotation, so it doesn’t describe twist at all.