What is the difference between ejector marks and breech marks?
The breech face rests against the head of the cartridge case and holds the cartridge case in the chamber of the firearm. Ejector marks are sometimes created when cartridges or cartridge cases are ejected from the action of a firearm.
What causes breech face marks in the cartridge head?
Breech face marks- These marks come from the area surrounding the firing pin of the gun. After the cartridge powder is ignited by the firing pin striking the primer cup, tremendous pressure is exerted in the chamber of the weapon, forcing the back of the cartridge case against the breech face of the weapon.
What are three different types of breech face marks?
There are three types of breech presentation: complete, incomplete, and frank.
What are breech face markings?
The breech face is the area of the firearm that supports the head of the cartridge case during the firing process. The breech face leaves markings on the head of the cartridge case, as expanding gases push the cartridge case back against the breech face.
What three types of marks are left on the casing after a gun is fired?
This cartridge case shows the three distinct marks, or ‘signatures,’ impressed on its surface when it was fired by a gun: the firing pin impression (FP), the breech face impression (BF) and the ejector mark (EM).
Where are ejector marks found?
Markings created on *cartridge cases by the metal-to-metal contact between the cartridge case and the extractor and ejector mechanisms in the weapon. The extractor mechanism removes a cartridge from the chamber, while the ejector throws the cartridge away once it is extracted.
What are extractor and ejector marks and what kind of weapons do these marks come from?
Extractor and ejector marks are produced when the cartridge case is mechanically extracted from the chamber and ejected and are visible as fine striations and gouged impressions on the rim and head of the case. Casings contain information about the type of ammunition, stamped onto the base of the cartridge.
Why are striation marks unique?
By examining unique striations, scratches left behind on the bullet and weapon, individual fired rounds can be, but not always are, linked back to a specific weapon. These striations are due to the rifling inside the barrel of handguns. Rifling spins the bullet when it is shot out of the barrel to improve accuracy.
What is the fastest weapon known today?
Short Bytes: The Metal Storm gun beats the Guinness World Records holder machine gun M134 Minigun by a great margin. Known as Metal Storm gun, this weapon system fires about 1 million rounds per minute.
What is the difference between ejector and extractor?
The extractor mechanism removes a cartridge from the chamber, while the ejector throws the cartridge away once it is extracted.
How are cartridge cases identified by breech marks?
Most fired cartridge cases are identified as having been fired by a specific firearm through the identification of breech marks. Very high pressures are generated within a firearm when a cartridge is discharged. These pressures force the bullet from the cartridge case and down the barrel at very high velocities.
Where do breech face marks come from on a gun?
cartridge. Breech face marks- These marks come from the area surrounding the firing pin of the gun. After the cartridge powder is ignited by the firing pin striking the primer cup, tremendous pressure is exerted in the chamber of the weapon, forcing the back of the cartridge case against the breech face of the weapon.
What is the medical term for stretch marks?
Stretch marks, the medical term for which is striae (striae distensae; striae atrophicus), are common skin findings which typically develop in the first half of life. They are usually benign but may be a source of cosmetic concern to patients.
What does striae stand for in dermatology terms?
Infrequently, striae may indicate the presence of a more concerning medical condition such as Cushing disease or overuse of systemic or topical corticosteroids. Clinically striae appear initially as asymmetric, raised, red linear streaks (striae rubrae) that tend to flatten and lighten over time.