Base Ops Flashcards
Breechblock
Seals the breech and blocks gases from exiting the chamber. Gives gases direction
Cartridge
Consists of cartridge case and bullet
Cartridge case
Does not contain a bullet
Fluted chamber
Slots cut into the chamber which allow gases from fired cartridge to enter the chamber and create a buffer between case and chamber wall that aids in extraction of cartridge case
Will leave horizontal burn marks on the case
Lands
Raised portion of rifling that impart the spinning motion
Grooves
The valley portion that in conjunction with lands impart spinning motion
Extractor
Component that engages extractor grooves on the cartridge case. Used to pull the case from the chamber
attached to the bolt
Internal Ballistics
All that happens within a firearm from the moment the primer ignites until the bullet leaves the barrel
External ballistics
Concerned with the path of the bullet from the muzzle to the target
Terminal ballistics
What happens to the bullet after it hits the target and what the bullet actually does to the target upon impact
Caliber
The distance across the bore of a weapon measured from land to land expressed in hundredths of an inch
Trajectory
The path of the bullet from the muzzle to the target
- Rising branch
- Maximum ordinate
- Falling branch
Bullet will never rise above bore line
5 types of firing
Single Action Double Action Semi-Auto only Auto-only Selective fire
Single Action
The weapon will only fire when it has been manually cocked
Double action
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
Semi-Auto only
The weapon will fire only one round per pull of the trigger
Auto-Only
The weapon will fire continuously until the trigger is released
Selective Fire
The weapon can fire semi-auto or fully auto
MOA->Inch
1 MOA= 1.047 inches or 1 inch at 100 yards
MOA->cm
1 MOA= 2.87cm or 3cm at 100m
MIL->MOA
1 MIL=3.375 MOA or 3.5 MOA
Types of Feeding Mechanisms
Magazines
Belts
Clips
Types of Magazines
Box (Staggered/In-line)
Pan
Drum
Types of Belts
Split Link
Fully Incased Link
Disintegrating Link
Non-Disintegrating Link
types of clips
Stripper
En-Block
Types of military Cartridge
Rimmed Semi-Rimmed Rimless Belt Rebated
Types of Ammo
Center Fire
Rim Fire
parts of cartridge
Bullet
Case
Primer
Powder
types of bullet tips
Spitzer
Round Nose
Choke
Tapered constriction at the muzzle end of a shotgun’s barrel
Increases effective range
types of chokes
Full
Modified
Improved cylinder
Cylinder
Breech
The outside rear face of the barrel that meets the face of the bolt
Headspace
The distance from the breechblock to the part of the chamber that stops forward movement of the cartridge case
Muzzle Brake
Device attached to end of muzzle that deflects emerging gases. Energy imparted pulls weapon forward to offset rearward recoil
Rifling
Spiral grooves in the bore of the barrel which impart a spinning motion on the bullet
Ejector
Presses against cartridge case to push it out of the mechanism
- 180* opposite of the ejection port
- Fixed or spring loaded
Disconnector
Prevents the firing of more than one shot per pull of the trigger. Prevents firing until the action is fully closed
Sear
Component retained under spring tension that releases, by means of a trigger, either a firing pin, hammer, or bolt
Trigger
Finger actuated lever that activated the firing mechanism. When pulled, fires the weapon
Battle Sight
The range at which you can hit a target between the throat and waist without making a sight adjustment
Trigger Bar
Mere extension of the trigger. Connects the sear and trigger
Ballistics
The study and science of the motion and impact of projectiles
5 categories of firing pins
Free floating Striker Percussion Inertia Fixed
3 types of ballistics
Internal
External
Terminal
8 types of locking systems
Rotating bolt Rising/lowering bolt Swinging bolt Rotating barrel Rising barrel Locking flaps Locking block Roller
8 cycles of operation
Feeding Chambering Locking Firing Unlocking Extracting Ejecting Cocking
8 types of operating systems
Bolt action Blowback Delayed blowback Recoil Recoil with gas assist Gas operated Manual pump Rotating cylinder
3 types of gas operated
Gas blast
Gas tappet
Gas direct
types of primer
Boxer (reloadable, one flash hole)
Berdan (two flash holes)
4 rules of weapon safety
Treat every weapon as if it’s loaded
Never aim at something you aren’t willing to destroy
Keep your finger off the trigger until ready to fire
Be sure of your target and what’s beyond it
Angular Measurements
1 MIL= 10cm at 100m
= 1m at 1,000m or 1km
Hybrid muzzle device
Combined reduction in flash signature, recoil, and muzzle climb
Compensator
Device attached to muzzle allowing gases to be deflected upward through the top slots. Lower portion is solid causing gases to push muzzle down, retarding muzzle climb
Flash suppressor
3 or 4 pronged device attached to the muzzle designed to cool hot gases as they leave the muzzle behind the round, reducing flash
3 ways to measure headspace
- Pistol cartridge= breechblock->straight wall/mouth of the cartridge case
- Rimmed Case= just the width of the rim
- Rimless case= breechblock->Datum line
Silencer
Device attached to muzzle end of firearm which muffles the sound of the expanding gases when a round is discharged
Types of muzzle devices
- Flash suppressor
- Muzzle brake
- Compensator
- Hybrids
Shot shell components
Crimp Case Shot Wad Powder charge Brass head Primer
Civilian cartridge measurement (caliber)
The distance across the bore of a weapon, measured from land to land, expressed in hundredths of an inch
Military cartridge measurement
Bullet diameter x cartridge case length expressed in mm
Bullet bases
Boat tail
Flat base
Types of recoil operating systems
- Long action= barrel and bolt recoil all the way back as a complete unit
- Short action= barrel and bolt recoil only a short distance together before unlocking and separating. (Glock)
- Inertia action= entire firearm recoils while the bolt stays in place (Bennelli)
