The M61A1 is a gun type that fires at what caliber?

The M61A1 is a gun type that fires at what caliber?

• A. 20 MM
• B. 25 MM
• C. 30 MM
• D. 12.7 MM

Answer: (A)

The main idea here is knowing the actual caliber of the M61A1. The M61A1 is a six-barrel rotary cannon, widely known as the Vulcan, and it fires 20-millimeter rounds. Caliber means the diameter of the bore and the projectile, so the M61A1’s ammunition is 20 millimeters in diameter. That’s why this is the best answer. The other options correspond to different weapons with larger or smaller calibers—25mm and 30mm are used by other autocannons, and 12.7mm is the .50 caliber used by heavy machine guns—not the M61A1.

The main idea here is knowing the actual caliber of the M61A1. The M61A1 is a six-barrel rotary cannon, widely known as the Vulcan, and it fires 20-millimeter rounds. Caliber means the diameter of the bore and the projectile, so the M61A1’s ammunition is 20 millimeters in diameter. That’s why this is the best answer. The other options correspond to different weapons with larger or smaller calibers—25mm and 30mm are used by other autocannons, and 12.7mm is the .50 caliber used by heavy machine guns—not the M61A1.