FBI Ammunition & Ballistics 2 — Questions and Answers
Question 1: What is 'bullet drop' in external ballistics?
- The decrease in bullet weight over distance
- The downward deviation of a bullet's path caused by gravity (Correct answer)
- The loss of bullet spin stabilization over distance
- The reduction in bullet velocity at extended range
Correct answer: The downward deviation of a bullet's path caused by gravity
Bullet drop is the downward curve in a bullet's trajectory caused by gravity continuously pulling the projectile downward during its flight.
Question 2: Why is 'overpenetration' a critical concern for FBI agents in populated environments?
- It causes excessive barrel wear
- A bullet that exits a target continues traveling and may strike unintended persons (Correct answer)
- It reduces the accuracy of follow-up shots
- It increases the risk of ricochet off hard surfaces
Correct answer: A bullet that exits a target continues traveling and may strike unintended persons
Overpenetration occurs when a bullet passes completely through the intended target and continues, posing a lethal threat to bystanders or other unintended targets.
Question 3: What factor most significantly determines a bullet's ability to retain velocity at long range?
- The color or coating of the bullet
- The bullet's ballistic coefficient (BC) (Correct answer)
- The ambient temperature at the time of firing
- The caliber designation of the firearm
Correct answer: The bullet's ballistic coefficient (BC)
The ballistic coefficient (BC) is a numerical value that quantifies how efficiently a bullet overcomes air resistance; a higher BC means the bullet retains velocity better over distance.
Question 4: What is the primary purpose of rifling in a gun barrel?
- To increase the barrel's resistance to heat and wear
- To reduce the sound signature of the firearm
- To impart spin on the bullet for gyroscopic stability and improved accuracy (Correct answer)
- To slow the rate of fire to safe levels
Correct answer: To impart spin on the bullet for gyroscopic stability and improved accuracy
Rifling consists of helical grooves machined into the bore that spin the bullet as it travels down the barrel, providing gyroscopic stability and dramatically improving long-range accuracy.
Question 5: Which standard handgun cartridge did the FBI adopt in 2015, replacing the .40 S&W?
- .45 ACP
- .357 SIG
- 9mm Luger (9x19mm) (Correct answer)
- 10mm Auto
Correct answer: 9mm Luger (9x19mm)
The FBI transitioned back to the 9mm cartridge in 2015, citing modern hollow point advancements that equaled .40 S&W terminal performance, combined with reduced recoil and higher capacity.
Question 6: What is 'sectional density' in bullet performance?
- The ratio of bullet weight to its cross-sectional area, indicating penetration potential (Correct answer)
- The hardness rating of the bullet's jacket material
- The ratio of bullet length to its diameter
- The surface area of the bullet's base in square inches
Correct answer: The ratio of bullet weight to its cross-sectional area, indicating penetration potential
Sectional density is the ratio of bullet mass to its cross-sectional area; a higher value generally indicates greater potential for deep penetration.
Question 7: What is a 'frangible' bullet, and what is its primary law enforcement application?
- A bullet that expands in soft tissue to maximize energy transfer
- A bullet designed to disintegrate on hard surfaces, reducing ricochet hazards during close-range training (Correct answer)
- A bullet with a hollow base for better gas sealing in the bore
- A Teflon-coated bullet designed to defeat soft body armor
Correct answer: A bullet designed to disintegrate on hard surfaces, reducing ricochet hazards during close-range training
Frangible bullets are made from compressed metal powder and break apart upon striking hard surfaces, making them ideal for indoor range training where ricochet is a safety concern.
FBI Ammunition & Ballistics 2
What is 'bullet drop' in external ballistics?