NRA NRA Ammunition & Ballistics Fundamentals

Question 1

What are the four basic components of a centerfire metallic cartridge?

Accepted Answer

Case, primer, powder, bullet

Answer

Shell, cap, charge, projectile

Answer

Brass, percussion cap, powder, slug

Answer

Neck, head, primer, projectile

Question 2

What distinguishes a rimfire cartridge from a centerfire cartridge?

Accepted Answer

The priming compound is inside the rim of the case head

Answer

Rimfire uses a larger primer

Answer

Rimfire cases are reloadable

Answer

The bullet is seated below the case mouth

Question 3

What is the purpose of the crimp on a cartridge?

Accepted Answer

It secures the bullet in the case and prevents movement during feeding

Answer

It increases bullet velocity

Answer

It centers the primer in the pocket

Answer

It seals the case to prevent moisture

Question 4

What does the term 'SAAMI' stand for and why is it relevant to gunsmiths?

Accepted Answer

Sporting Arms and Ammunition Manufacturers' Institute — sets standardized cartridge and chamber specifications

Answer

Society of American Arms & Munitions Industries — sets bore tolerances

Answer

Small Arms Ammunition Manufacturers Index — lists approved powders

Answer

Standard American Armament and Manufacturing Institute — regulates barrel lengths

Question 5

What is 'bullet setback' and why is it dangerous?

Accepted Answer

When the bullet is pushed deeper into the case, increasing chamber pressure

Answer

When the bullet exits at an angle

Answer

When the bullet fails to engage the rifling

Answer

When the bullet is seated too far out causing feed failures

Question 6

What is the function of a Boxer primer compared to a Berdan primer?

Accepted Answer

Boxer has a single central flash hole and self-contained anvil; Berdan has two offset flash holes and uses the case anvil

Answer

Boxer uses two flash holes; Berdan uses one central flash hole

Answer

They are identical in function and interchangeable

Answer

Boxer primers are larger and used only in magnum cartridges