Firearm Competency Ammunition Types and Ballistics 2

Question 1

What is meant by 'muzzle velocity' in ballistics?

Accepted Answer

The speed of the bullet at the moment it exits the barrel

Answer

Muzzle velocity is the speed of the bullet as it leaves the muzzle of the firearm, typically measured in metres per second (m/s) or feet per second (fps).

Question 2

What is the key difference between rimfire and centrefire cartridges?

Accepted Answer

The primer location: rimfire has primer in the rim, centrefire has primer in the centre of the base

Answer

In rimfire cartridges the primer compound is contained within the hollow rim of the case, whereas centrefire cartridges have a separate, replaceable primer in the centre of the base.

Question 3

What does a '+P' marking on a box of ammunition indicate?

Accepted Answer

The ammunition is loaded to higher-than-standard pressure

Answer

+P indicates overpressure ammunition loaded to higher chamber pressures than standard, which increases velocity but should only be used in firearms rated for it.

Question 4

What unit is commonly used to express bullet weight in ammunition specifications?

Accepted Answer

Grains

Answer

Bullet weight is conventionally measured in grains (gr), where one grain equals approximately 0.0648 grams, allowing for precise specification of bullet mass.

Question 5

What is a soft point (SP) bullet designed to do compared to a full metal jacket?

Accepted Answer

Expand upon impact while retaining more mass than a hollow point

Answer

A soft point bullet has an exposed lead tip that causes controlled expansion on impact, making it suitable for hunting as it transfers energy efficiently while retaining mass.

Firearm Competency Test

Firearm Competency Test

Firearm Competency Ammunition Types and Ballistics 2