criminalistics part 3,4

19問 • 3年前

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. Most modern center-fire cartridge cases of are this type, since this case from provides the greatest powder capacity commensurate with the overall case length.

Bottleneck

This refers to the projecting metal that serves the purpose of limiting the forward travel of cartridge into the chambers and thus also limits the clearance, if any, between the heads and the supporting parts of the cartridge case.

Rim

. This refers to the bottle of “cork” that holds the bullet at the front or plugs the breech of the barrel against the escape of the gas, and the gun powder inside the case that powers the bullet on its trip down the barrel

Head and Body

refers to the serrated grooves that are sometimes found rolled in the necks and bodies of the cases at the of the bases of the bullet to prevent it from being pushed back or loosened.

Shell cannelures

it is applied to that part of the cartridge case that is occupied by the bullet.

neck

This is the portion the cartridge case that supports the neck. In many of the earliest cartridge designs, case shoulders were very long and sloping, making them difficult to reliably headspace on the shoulder.

Shoulder

It is the circular groove neat the base of the case or shell designed for the automatic withdrawal of the case after such firing.

Extracting Groove

These bullets are made with an explosive or flammable mixture in the tip that is designed to ignite on contact with a target.

Incendiary

. These have a hollow back, filled with a flare material. Usually this is a mixture of magnesium metal, a perchlorate, And strontium salts to yield a bright red color, although other materials providing other colors have also sometimes been used.

Tracer

Jacketed designs where the core material is a very hard, high-density metal such tungsten, tungsten as carbide, depleted uranium, or steel.

Armor Piercing

. Bullets made using cores from powdered metals other than lead with binder or sometimes sintered.

Blended-Metal

The primer is that portion of the cartridge which consists of a brass or gliding metal cup. The cup contains a highly sensitive mixture of chemical compound, which when struck by the firing pin would detonated to ignite. Such action is called “_________.

percussion

Designed to disintegrate into tiny particles upon impact to minimize their penetration for reasons of range safety, to limit environmental impact, or to limit the shoot-through danger behind the intended target, example is the Glaser Safety Slug.

Frangible

In the ____________, the anvil is a separate piece affixed into the primer’s cup, and bottoming out in the primer pocke when the primer is seated.

Boxer system

utilizes an integral anvil, formed into the base of the primer pocket. Additionally, Boxer primed cases utilize a single, fairly large, centrally located flash hole, making them eminently suitable for reloading.

Berdan system

use a compound called potassium chlorate as part of the priming mixture. When the primer detonates, the chemical reaction changes this compound to potassium

Corrosive primer

. It contains dinol as the explosive. Manganese dioxide as the oxidizer, tetrazene as the sensitizer and glass as the co-sensitizer.

Non-Corrosive Primer

It is the actual priming compound placed into the cup. All modern primers are both noncorrosive, and non-mercuric.

Pellet

Made of shellacked paper despite its name, the foil is a small circular disc placed between the priming pellet and the anvil.

Foil

Lea set A

Christian Jay Santos · 53問 · 3年前

Lea set A