Basic Operations Flashcards
What are the 8 cycles of Operation?
Feeding Chambering Locking Firing Unlocking Extracting Ejecting Cocking
Three types of magazines
Box (Staggered and inline)
Drum
Pan
Three types of feeding mechanisms
Magazines
Belts
Clips
Four types of belts…
SLD
SLND
FED
FEND
Two types of clips
En-bloc Clip
Stripper Clip
Five types of Cartridges
Rimmed Semi-rimmed Rimless Belted Rebated
What are the five types of Firing pins?
Free floating Inertia Percussion Striker Fixed
What are the three ways pins receive energy?
A larger mass strikes them
A spring provides energy
Their own mass provides energy
Two types of primers
Boxer
Berdan
What are the eight locking systems?
Rotating Bolt Rising/Lowering Bolt Roller Rising Barrel Locking Flaps Swinging Bolt Locking Block Rotating Barrel
What are the eight operating systems?
Bolt Action Blowback Delayed Blowback Recoil Recoil with Gas Assist Gas Operation Manual Pump Revolving Cylinder
What are the three types of gas operation?
Gas Blast
Gas Tappet
Gas Direct
What is a Disconnector?
A device incorporated into the action of a weapon which prevents the firing of more than on shot for one pull of the Trigger, or which prevents the weapon from being fired until the action is fully closed.
What does a compensator do?
Deflects gases upward in order to retard muzzle climb.
What does a flash suppressor do?
Cools the hot gases as the round leaves the muzzle, which reduces the flash.
What are grooves?
The portion of the rifling in the barrel that works in conjunction with the lands to impart spinning motion on a bullet.
What is a hangfire?
A delay in the ignition of the powder charge, unpredictable and dangerous.
What is a ‘Hold Open Device’?
A component in a weapon designed to hold the bolt to the rear when it is out of ammunition.
What is a muzzle brake?
A device on the muzzle that deflects gases and pulls the weapon forward to offset some of the recoil.
What is muzzle velocity?
Velocity in Feet Per Second at which the bullet leaves the barrel.
What is pitch?
The angle at which the rifling is cut in relation to the axis of the borrow. Expressed as the length of the bore for one complete turn/spiral.
What is a sear?
A component retained under spring tension that releases, by means of a trigger, either a firing pin, hammer, or bolt.
What are the three rates of fire?
Sustained
Rapid
Cyclic
What is a breechblock?
A component that seals the breech and blocks gases from the fired cartridge.
What is the chamber?
The unrifled portion of the bore at the rear end of the barrel that receives and supports the cartridge when the breech is closed. It aligns the bullet with the bore and the primer with the firing pin.
What is an accelerator?
A device that operates during the rearward movement of the recoiling parts to increase the speed at which certain parts move.
What is headspace?
The distance from the breechblock to that part of the chamber which stops the forward movement of the cartridge case.
What are the two types of flash supressors?
Duckbill
Bird Cage
What leaves burn marks on spent cartridge casings?
A fluted chamber.
What is a fluted chamber used for?
Used to maximize energy for extraction. Commonly found in HKs
What is a trigger bar?
Operates between the Trigger and the sear, essentially an extension of the trigger.
How many Minutes of Angle are in 1 degree?
60 minutes
What are the three most common compositions of cartridge casings?
Brass (ideal) 70% copper, 30% zinc
Aluminum (weaker than brass)
Steel (Usually coated in a laquer)
How many flash holes does a Berdan primer have?
2
How is a military round measured?
Bullet Diameter X Cartridge Case Length
How is a civilian caliber measured?
Across the bore, land to land, in 1/100ths of an inch
