Small Arms Terminology

Question 1

Breechblock

Answer 1

The component which seals the breech and blocks gases from the fired cartridge from exiting to the rear of the chamber. (Bolts in rifles and machine guns, inside of the slide in pistols)

Question 2

Headspace

Answer 2

The distance from the breech face to the part of the chamber that stops the forward movement of the cartridge case.

Question 3

Muzzle Break

Answer 3

A device which deflects the gases as they exit the muzzle of the weapon, helps to reduce some of the felt recoil.

Question 4

Fluted Chambers

Answer 4

A fluted chamber will leave horizontal “burn” marks on the spent cartridge case produced by the gases that cycle the weapon.

Question 5

Rifling

Answer 5

Helix grooves in the bore of the weapon spin the bullet for accuracy commonly referred to as “lands and grooves”

Question 6

Extractor

Answer 6

A device which attaches to the rear of the cartridge groove or rim, utilized to pull the cartridge from the chamber.

Question 7

Ejector

Answer 7

180 degrees opposite from the ejection port. May also be a tang of metal attached to the receiver, this is normally indicated by a cut out on the bolt group.

Question 8

Disconnector

Answer 8

A device which prevents the firing of more than one round for one pull of the trigger, or prevents the weapon from being fired until the action is fully closed.

Question 9

Sear

Answer 9

Component retained under spring tension that releases, by means of the trigger, either a firing pin, hammer, or bolt.

Question 10

Trigger

Answer 10

A finger actuated lever used to activate the firing mechanism thus firing the weapon.

Question 11

Trigger Bar

Answer 11

A connecting bar operating between the trigger and sear. Nothing more than an extension of the trigger.

Question 12

Ballistics

Answer 12

The study of projectiles from the time of shooting to the time of impact.

Question 13

Internal Ballistics

Answer 13

The study of the motion of a projectile in a gun barrel or tube. Simply put, it is everything that happens within the firearm from primer ignition until the projectile leaves the barrel.

Question 14

External Ballistics

Answer 14

The study of the motion of a projectile in flight from the time it leaves the muzzle until it impacts the target.

Question 15

Terminal Ballistics

Answer 15

The study of what happens to the projectile after it hits the target and what the projectile actually does to the target upon impact.

Question 16

Trajectory

Answer 16

Bullet trajectory is the path the bullet takes from the muzzle of the weapon to the target. The bullet will being to drop immediately upon exiting the weapon due to gravity and atmospheric resistance.

Question 17

Types of Firing

Answer 17

Single Action, Double Action, Semi Auto, Automatic, Selective Fire.

Question 18

Single Action

Answer 18

The weapon will only fire when it has been manually cocked. (The slide pulled to the rear of a automatic pistol or the hammer being pulled rearward on a revolver.

Question 19

Double Action

Answer 19

The trigger bar will cock the weapon when the trigger is pulled and the sear will release the hammer when the trigger has reached its maximum rearward movement.

Question 20

Semi-Auto only

Answer 20

The weapon will fire only one round per pull of the trigger. After that the trigger and disconnector must be reset before the next round can fire.

Question 21

Automatic Only

Answer 21

The weapon will fire continuously until the trigger is released (re-engaging the sear) or all ammunition is expended.

Question 22

Selective Fire

Answer 22

The weapon can fire semi-automatic or automatic. Burst-firing of a set number of rounds per squeeze of the trigger 2,3,4 ect.