CHAPTER 4-5 Flashcards
– refers to the tubular casing or shell of an ammunition that holds the bullet and contains the gunpowder.
Cartridge Case
Parts of Cartridge Case
- Mouth – the edge of shell’s opening.
- Crimp – part of mouth that is turned in upon the bullet.
- Shell Cannelures - are the serrated groves around the neck
- Neck - occupied by the bullet.
- Shoulder - supports the neck.
- Body – contains gunpowder
- Extracting groove - the circular groove near the base of the shell designed for the automatic withdrawal of the case after firing.
- Rim - limits the forward travel of cartridges into the chamber.
- Primer – located at central base that contains the priming mixture.
- Shell Head – the base portion that contains the head stamp
– is used secure the bullet in the shell to avoid being moved or loosened from its gripped
Crimp
– used only on jacketed ammo that consists of dimples or grooves pressed into the mouth.
Stab or Ring Crimp
– used in the cartridge with headspace on the cartridge case mouth with lead bullets.
Taper Crimp
– located at the neck that is rolled into the groove of the bullet.
Roll Crimp
– rim diameter is greater than the body (Cal .38 and Cal .22)
Rimmed
– rim diameter is SLIGHTLY greater than the body (Cal .25, Cal .32 auto, Cal .38 Super)
Semi-rimmed
– rim is equal with the body (Cal 5.56mm, Cal .30, 9mm, Cal .45)
Rimless
– rim is smaller than the body (Cal 8mm x 59)
Rebated
– a protruding metal is belted around the shell (Cal .338 magnum, 13.9 x 99)
Belted
– found on the primer (particularly on the primer cup).
Note: Glock Pistols have rectangular firing pin marks.
Firing Pin Marks
– found on the base of shell. Caused by the breechface
Breechface Marks
– found on the extracting groove
Extractor Marks
– located at the rim at the base of shell fired from automatic FAs
Ejector Marks
– found on the primer near the firing pin mark. It is just a rebound or duplication of firing pin mark.
Shearing Marks (Secondary Firing Pin Marks)
– found on the body of shell. Caused by the magazine lips during loading
Magazine Marks
– found on the body of the shell. Caused by the irregularities inside the chamber
Chamber Marks
– found on the base of rimmed type shell. Caused by Break Type Revolver during loading
Pivotal Marks
– found on the side of the rim. Caused by the contact between the shell and ejection port of the FA (Pistol)
Ejector Port Marks
– part of cartridge consisting of lead or jacketed projectile projected from FA. Bullets in the crime scene are also called Slugs.
Bullet
The word bullet came from the French word “boulette” which means “small ball.”
bullet
– are spherical projectiles used in smoothbore FAs.
Shot/ Pellets/ Balls
Note: The general term for bullets, shots/pellets/ balls is Projectile.
– means a Small ball.
French word “boulette
bullet is called
slug
In gov’t parlance, a cartridge containing bullet is called
Ball Cartridge
In small arms ammunition, bullet refers to the projectile which is
Cylindrical or Cylo-conoidal
– made of lead or alloy of metals, tin and antimony
Lead Bullets
– made of lead core covered with jacket of harder material, such as gilding metal, copper alloy approximately 90% and zinc 10%.
Jacketed Bullets
– have soft lead core inside a jacket.
Ball Bullets
– contains tungsten chrome steel and are fired at vehicles and other armored targets
Armor Piercing Bullets
– contains compound at the base, usually similar to barium nitrates which set fire when bullet is projected.
Tracer Bullets
– contains phosphorous or other materials that can set fire. These are used for targets such as aircrafts and/or gasoline depot.
Incendiary Bullets
– contain a high charge of explosive usually limited to 20mm and above.
Explosive (Fragmentary Bullets)
Parts of Bullet
- Base – receives the thrust and heat from the burning gunpowder. Sometimes Gas Check is placed to prevent melting of bullet.
- Bearing Surface – body of the bullet that contacts the lands and grooves in the barrel. This should fit the bore.
- Bullet Cannelure – serrated groove or depression around the body of bullet, usually used in bottle neck shell.
- Core – a mass of lead in a bullet covered with jacket. This sometimes, contains other metals for other purposes.
- Head height – length in the portion of the bullet from the shoulder to the tip.
- Heel – the edge of the base
- Jacket – covers the entire lead core, usually copper, brass, steel and aluminum.
- Meplat diameter– the diameter of the nose/ogive. 9. Ogive/ Nose – the tapered or curved part of the bullet towards the tip of a bullet.
- Point – the forward portion or tip of bullet.
- Shoulder – the end portion of the body of bullet. Bullets Designed for Handgun
– has an exposed lead and has cavity at the tip.
Jacketed Hallow Point
– with more exposed lead at the tip that expand more than a hallow point bullet.
Semi-jacketed Hallow Point
– the lead core is enclosed by a light copper jacket, with cone shape and flat point.
Full Metal Cone (Truncated Cone)
– a solid lead bullet with rounded ogive for downrange accuracy, hard hitting, economical, generally designed bullet for revolvers.
Lead Round Nose
– a solid lead bullet, cuts clean in paper targets for precise scoring.
Lead Full-Wadcutter
– solid lead bullet with semi pointed nose, with sharp shoulder for clean hole punching in paper target.
Lead Semi-wadcutter
– lead core is covered with jacket except the base, results to little expansion but with deep penetration.
Full Metal Jacket
– the lead core is enclosed by heavy copper jacket results to little or no expansion BUT deep penetration.
Full Metal Jacket Boat Tail
– extremely accurate designed aerodynamically
Hallow Point Boat Tail
exposed lead on the tip of the bullet with broader point diameter. The bullet may expand and may result to more or less 200% of the original bullet diameter.
Soft Point
– having a copper sheath with full metal jacket.
Hardball Bullet
– designed for armored penetration at a greater distance
Depleted Uranium Bullet
– the lead core is jacketed by copper-alloy or aluminum. The jacket is designed to be disintegrated into small pieces to cause hemorrhage.
Silver Tip Bullet
- upon reaching target, splits into fragments when hitting soft tissue creating bigger wound. It may have stress lines around the bullet
Fragmentation Bullet
– have sharp pointed nose, more effective than the round ball of the same weight. These have more velocity. It may travel sideways inside the target upon hitting bones/hard object. Spitz means pointed.
Spitzer Bullets
– include all soft point bullets, split nose bullets, hallow point bullets and jacketed bullets with exposed lead core. These bullets are designed for expansion.
Dumdum Bullets
– designed to expand upon striking the target, thus leaving a smaller entry but larger/bigger exit.
. Mushroom Bullet (Soft Point Bullet)
– has open ogive/nose designed to increase the expansion upon hitting the target.
Hallow Point Bullet (Express Bullet
– is plated with gilding metal to prevent rusting and to reduce frictional resistance in the bore.
Steel Jacketed Bullet
– a solid copper with no lead core, no jacket and is heat treated for extra toughness. Upon hitting hard target, nose peels to four razor-edge petals. Designed by Barne in 1989 and owned by Randy Brooks.
X-Bullet
– uses a special jacket and compressed shot core with plastic tip. It has a high performance ammunition that gives superior penetration to solid targets.
Glaser Safety Slug
MARKS FOUND ON BULLET
- Rifling Marks – caused by the land and grooves
- Skid Marks – caused by the initial forward movement of bullet before the rifling get the bullet. 3. Slippage Marks – caused by worn-out, oversized and oily barrel.
- Shaving/Stripping Marks (Tapyas sa bala) – found on the nose or ogive of a bullet, done when the bullet and the barrel are not aligned.
- Miscellaneous Marks – caused by various parts or external objects other than the firing pin, rifling & magazine.
