NRA NRA Ammunition & Ballistics 1 — Questions and Answers
Question 1: What are the four components of a centerfire cartridge?
- Bullet, case, primer, powder (Correct answer)
- Bullet, case, wad, powder
- Projectile, shell, cap, propellant
- Slug, brass, igniter, charge
Correct answer: Bullet, case, primer, powder
A standard centerfire cartridge consists of a bullet (projectile), a case (brass or steel), a primer, and propellant powder.
Question 2: What is the difference between a boxer primer and a berdan primer?
- Boxer has a single flash hole and self-contained anvil; Berdan has two flash holes and relies on an anvil in the case (Correct answer)
- Boxer uses a softer metal; Berdan uses a harder metal
- Boxer is used in rifle ammo only; Berdan is for pistols
- Boxer is reloadable; Berdan is not
Correct answer: Boxer has a single flash hole and self-contained anvil; Berdan has two flash holes and relies on an anvil in the case
Boxer primers are self-contained with an internal anvil and a single central flash hole, making them easy to reload; Berdan primers use two off-center flash holes with the anvil formed into the case.
Question 3: What does SAAMI stand for and why is it important to gunsmiths?
- Sporting Arms and Ammunition Manufacturers' Institute; it sets industry standards for chamber and ammunition dimensions (Correct answer)
- Small Arms Ammunition Management Institute; it regulates importation
- State Approved Arms and Munitions Ministry; it governs licensing
- Standard Ammunition and Arms Military Index; it provides ballistic data
Correct answer: Sporting Arms and Ammunition Manufacturers' Institute; it sets industry standards for chamber and ammunition dimensions
SAAMI (Sporting Arms and Ammunition Manufacturers' Institute) establishes the dimensional and pressure standards that ensure safe interchangeability of ammunition and firearms.
Question 4: What is the primary difference between rifle powder and pistol powder in terms of burn rate?
- Rifle powder burns slower; pistol powder burns faster (Correct answer)
- Rifle powder burns faster; pistol powder burns slower
- Both burn at the same rate
- Burn rate depends on bullet weight, not firearm type
Correct answer: Rifle powder burns slower; pistol powder burns faster
Rifle powders are generally slower burning to build pressure progressively over a longer barrel, while pistol powders are faster burning to achieve peak pressure in shorter barrels.
Question 5: What is sectional density (SD) of a bullet?
- The ratio of bullet weight to its caliber squared, indicating penetration potential (Correct answer)
- The diameter of the bullet divided by its length
- The weight of the bullet relative to case volume
- The hardness rating of the bullet material
Correct answer: The ratio of bullet weight to its caliber squared, indicating penetration potential
Sectional density is the bullet's weight (in pounds) divided by the square of its diameter (in inches), and higher SD generally indicates better penetration.
Question 6: What is a Magnum cartridge generally characterized by?
- A heavier bullet only
- A larger case capacity resulting in higher velocity and energy compared to its standard counterpart (Correct answer)
- A larger bullet diameter
- A longer overall cartridge length only
Correct answer: A larger case capacity resulting in higher velocity and energy compared to its standard counterpart
Magnum cartridges are generally characterized by larger case capacity, which allows more powder for higher velocities and increased muzzle energy compared to standard cartridges of similar caliber.
NRA NRA Ammunition & Ballistics 1
What are the four components of a centerfire cartridge?