Small Arms Terminology Flashcards
What are the three types of ballistics?
1 Internal
2 external
3 terminal
Ballistics
The science and study of the motion and impact of projectiles.
Breechblock
A component that seals the breech and blocks gases from the fired cartridge from exiting to the rear of the chamber. (Bolts in rifles, inside the slide in pistols)
Disconnector
A device incorporated into the action of a weapon which prevents the firing of more than one shot for one trigger pull or which prevents the weapon from being fired until the action is fully closed (in battery).
Ejector
A cam or projection inside the receiver against which the cartridge case strikes and is thrown clear of the mechanism after it has been drawn from the chamber by the extractor.
Extractor
A component that engages the rim, or extractor groove of the cartridge case while the cartridge is in the chamber. After firing, the extractor withdraws the case from the chamber when the action opens.
Fluted chamber
Leaves horizontal burn marks on spent cartridge case produced by the gases that cycle weapon.
Firing pin
The part of the firing mechanism that strikes or contacts the primer of the cartridge to cause ignition to fire weapon.
Headspace
The distance from the breechblock to that part of the chamber which stops the forward movement of the cartridge case.
Muzzle brake
A device at the muzzle end of the weapon which deflects the emerging powder gases. The energy imparted by this act of deflection pulls the weapon forward to offset some of the rearward motion of recoil.
Rifling
A series of spiral grooves in the bore of a barrel which imparts a spinning motion to the bullet as it travels the length of the barrel from the breech to the muzzle.
What are the five methods for creating rifling?
1 cut rifling 2 broached 3 button 4 hammer forging 5 flow forming
What are the two profiles for rifling?
1 lands and grooves
2 polygonal
Sear
A component retained under spring tension that releases, be means of a trigger, either a firing pin, hammer or bolt.
Trigger
A finger actuated lever used to activate the firing mechanism to fire the weapon.
Trigger bar
A connecting bar operating in between the trigger and the seat. Nothing more than an extension of the trigger.
Single action (SA)
Requires manual cocking (eg slide or hammer pulled rearward).
Double action (DA)
The trigger bar cocks the weapon when the trigger is pulled and the sear releases the hammer when the trigger has reached maximum rearward movement.
What are five types of firing?
1 Single action (SA) 2 double action (DA) 3 semi-automatic only (semi-only) 4 automatic only (auto-only) 5 Selective fire (sel.-fire)
Trajectory
The path the bullet takes from the muzzle of the weapon to the target. The bullet will immediately begin to drop upon exiting the muzzle of the weapon due to atmospheric resistance and gravity.
What are the two types of sights?
1 Fixed
2 adjustable
How does the US military measure rounds?
By taking the diameter of the bullet by the length of the cartridge case in millimeters. (Eg 7.62 mm x 54 mm)
How does the civilian sector measure rounds?
Caliber calculated by taking the distance across the bore of the weapon, measured from land-to-land, and expressed in hundredths of an inch.
What are the three parts of trajectory?
1 rising branch
2 maximum ordinate
3 falling branch
What is a battle sight?
The range that allows you to hit a target between the throat and waist without sight adjustment. Exact range varies with caliber of weapon.
Flash suppressor
A three or four pronged device attached to the muzzle of a weapon designed to cool the hot gases as they leave the muzzle behind the round; cooling the gases reduces the flash.
What is the choke?
Constriction at the muzzle end of the barrel that condenses the shot to increase max effective range.
