Locking Sys/ Op Sys/ Sights/ Feeding/Cartridges/Shotguns Flashcards
Locking System
Used to maximize the pressure in the chamber as gases are forced in one direction which increases velocity and range.
- Rotating Bolt- M16, AK47
- Locking Block- M9, P38
- Rising/Lowering Bolt- 240
- Roller- MG3/7, MP5, G3A4
- Rising Barrel- 1911A
- Locking Flaps- RP-46, RPD, DSHK
- Swinging Bolt- SGM
- Rotating Barrel
Rotating Bolt
The bolt rotates left or right to lock behind the breech.
M16, AK47
Locking Bolt
Lugs that engage into recesses of the slide/receiver that allow for locking to occur.
M9, P38
Rising/Lowering Bolt
The rear of the bolt rises or lowers into a locking recess of the receiver.
Bolt does not actually lower; the bolt guide lowers as it drops in to the locking shoulder.
240
Roller
Rollers push out of the left and right sides of the bolt to lock in to the breech.
Delayed blowback operating system.
MG3/7, MP5, G3A4
Rising Barrel
The barrel rises up into the slide to lock the barrel and slide together.
1911A1
Locking Flaps
Loose plates located on the bolt swing out locking into recesses in the receiver.
RP-46, RPD, DSHK
Swinging Bolt
The rear of the bolt swings out of line with the bore into a locking recess.
SGM
Rotating Barrel
Instead of the bolt rotating, the barrel rotates.
Operating Systems
- Bolt Action
- Blowback (Simple)
- Delayed Blowback
- Recoil
- Recoil with Gas Assist
- Gas Operated
- Manual Pump
- Revolving Cylinder
Bolt Action
The operator manually retracts the bolt to eject the spent cartridge and to chamber a new round by pushing the bolt forward.
M24, Win 1903
Blowback (Simple)
Works by pressure from the fired cartridge.
Only has 6 Cycles of Function as there are no locking or unlocking mechanisms.
Characterized by having heavier bolts to act as breechblocks for longer periods of time since there is no locking or unlocking mechanism.
Uzi, M12, L2A3
Delayed Blowback
These weapons have a locking system, which means there is a delay long enough for the round and excess gas to leave the muzzle before the bolt is fully unlocked.
P7 Series
Recoil
Works by pressure from the fired round. The breech is locked so when the round is fired, the barrel moves to the rear with the breechblock or bolt in place. The breechblock remains to the rear while the barrel is forced forward by the spring. After the barrel is fully forward the breechblock is released, moving forward to chamber another round. 3 Types of Recoil Action Long Action Recoil Short Action Recoil Inertia Action Recoil
Recoil with Gas Assist
Internal piston taps on the barrel to assist in unlocking the bolt; increasing the rate of fire and reliability.
Gas Operated
Gases within the barrel are trapped and redirected 3 Types Gas Blast Gas Tappet Gas Direct
Gas Blast
Gas makes contact with a gas piston directly attached to the operation rod or slide.
AK
Gas Tappet
Gas makes contact with the gas piston which then makes contact with the operating rod. The gas pistons and operating rods are separate parts.
M60
Gas Direct
Gas goes out of the gas port into the gas tube and is carried directly to the bolt or bolt carrier.
M4
Fixed Sights
Pistols and sub machine guns typically have fixed sights because they are used in close distances.
Battle Sights
Range that allows you to hit the target between the throat and the waist without sight adjustment.
Exact range will vary depending upon the caliber of the weapon.
Feeding Mechanisms
- Magazines
- Belts
- Clips
Magazines
- Box- Staggered, In-Line (Single Stacked)
- Pan
- Drum
Belts
- Split Link Belt (SLB)- Does not go all the way around the cartridge.
- Fully Encased Link Belt (FLB)- Link does go all the way around the cartridge.
- Disintegrating Link Belt (DLB)- Each link breaks apart.
- Non-Disintegrating Link Belt (NDLB)- Links will stay together in clusters
Clips
Device used to rapidly load a magazine
* Stripper Clip, En-Block Clip
5 Cartridge Case Types
- Rimmed
- Semi-Rimmed
- Rimless
- Belted
- Rebated
Types of Ammo
- Center Fire
2. Rim Fire
4 Components of a Cartridge
- Bullet
- Powder
- Case
- Primer
2 Types of Primer
- Boxer (Reloadable)- Has an anvil built into the primer with flash powder built in. One flash hole.
- Berdan (Non-Reloadable)- Contains only the flash powder, the anvil is part of the cartridge case. Two flash holes.
2 Types of Bullet Tips
- Spitzer Tip
2. Round Nose
Types of Bullet Bases
- Flat Base
2. Boat Tale
Cartridge Case Measurement
Military- Bullet diameter x cartridge case length expressed in mm
Civilian (Caliber)- The distance across the bore of a weapon measured from land to land expressed in hundredths of an inch
Choke
The inside bore constriction at the muzzle end of the shotgun’s barrel is known as a “choke.” When a shot shell is fired, shot travels down the bore, exits the muzzle, and begins to spread out. Chokes also increase effective range.
Types of Chokes
- Full
- Modified
- Improved
- Cylinder (None)
Components of a Shot Shell
- Crimp
- Shot
- Case
- Wad
- Power
- Brass Head
- Primer
Shotgun Case Lengths
Standard- 2 3/4
Magnum- 3 and 3 1/2
3 Types of Recoil
Short Action
Long Action
Inertia
M1911A1 Sear Spring
Left Spring Arm- Places forward pressure on the sear
Center Spring Arm- Places upward pressure on the disconnector
Right Spring Arm- Places outward pressure on the grip safety
