FBI Ammunition & Ballistics 1 — Questions and Answers
Question 1: What penetration depth in ballistic gelatin does the FBI require handgun ammunition to achieve for approval?
- 6–8 inches
- 9–11 inches
- 12–18 inches (Correct answer)
- 20–24 inches
Correct answer: 12–18 inches
The FBI protocol requires a minimum of 12 inches and a maximum of 18 inches of penetration in calibrated 10% ballistic gelatin to ensure adequate terminal performance.
Question 2: What does 'caliber' refer to when describing a firearm cartridge?
- The weight of the bullet in grains
- The diameter of the bore measured in hundredths of an inch or millimeters (Correct answer)
- The length of the cartridge case
- The muzzle velocity of the projectile
Correct answer: The diameter of the bore measured in hundredths of an inch or millimeters
Caliber is the internal diameter of the gun barrel, expressed in hundredths of an inch (e.g., .40) or millimeters (e.g., 9mm).
Question 3: What is the primary purpose of hollow point ammunition in law enforcement use?
- To increase bullet velocity beyond supersonic speeds
- To reduce ammunition cost per round
- To expand upon impact and limit overpenetration (Correct answer)
- To improve accuracy at distances beyond 100 yards
Correct answer: To expand upon impact and limit overpenetration
Hollow point bullets are designed to expand upon contact with soft tissue, creating a larger wound channel while reducing overpenetration risk to bystanders.
Question 4: What does the abbreviation 'FMJ' stand for in ammunition terminology?
- Full Metal Jacket (Correct answer)
- Federal Marksman Jacketed
- Fast Moving Jacketed
- Full Magnum Jacketed
Correct answer: Full Metal Jacket
FMJ stands for Full Metal Jacket, where a harder metal shell encases the lead core, reducing barrel fouling; it is commonly used for training due to its lower cost.
Question 5: What is muzzle velocity?
- The speed of the bullet when it strikes the target
- The speed of the bullet as it exits the barrel (Correct answer)
- The velocity of the firearm's recoil
- The speed of expanding gases inside the chamber
Correct answer: The speed of the bullet as it exits the barrel
Muzzle velocity is the speed at which a projectile leaves the barrel of a firearm, typically measured in feet per second (fps).
Question 6: In ammunition terminology, what unit is a 'grain' (gr)?
- A unit of measurement for bullet weight (Correct answer)
- The texture classification of gunpowder
- The direction of a barrel's rifling twist
- The material composition rating of the bullet
Correct answer: A unit of measurement for bullet weight
A grain is a unit of weight used for bullets and powder charges, with 7,000 grains equal to one pound avoirdupois.
Question 7: What is 'terminal ballistics'?
- The study of how bullets travel through the air
- The study of a bullet's behavior inside the firearm
- The study of a projectile's behavior upon striking a target (Correct answer)
- The study of ammunition storage and shelf life
Correct answer: The study of a projectile's behavior upon striking a target
Terminal ballistics is the branch of ballistics that studies what happens when a projectile reaches its final destination, including penetration depth, expansion, and energy transfer.
FBI Ammunition & Ballistics 1
What penetration depth in ballistic gelatin does the FBI require handgun ammunition to achieve for approval?