Letter F

The Definition of FOPA

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FOPA

Firearm Owners' Protection Act of 1986. It is a United States federal law that revised many provisions of the Gun Control Act of 1968. It bans civilian ownership of machine guns manufactured after May 19, 1986. Firearms made and registered before that date are not affected. The law limits the Bureau of Alcohol, Tobacco and Firearms from inspecting gun dealers more than once a year, with follow-up inspections allowed only The law also specifically forbids the government from creating a national registry of gun ownership.


19 Other Firearms Definitions You Need To Know


Toplever

A lever on a break-open gun mounted to the top of the receiver which, when pushed with the thumb (normally) to the right, operates (usually) a Scott Spindle, which in turn withdraws (usually) a Purdey Underbolt from the bites in the lumps of the barrels, allowing them to hinge downwards and the gun to open.

CFL

Abbreviation for Concealed Firearms License.

Obturation

The process of a bullet expanding under pressure to fit the bore of the firearm, or a cartridge case expanding under pressure to seal the chamber.

Isosceles Stance

There are two basic variants of the Isosceles stance, the Traditional Isosceles and Modern Isosceles stance. In both Isosceles stances, the feet parallel pointing toward the target and are roughly shoulder width apart. Both arms are stretched almost equally forward with the gun centered forward, creating the triangular shape which gives the stance its name.

Caseless Ammunition

A type of small arms ammunition that eliminates the cartridge case that typically holds the primer, propellant, and projectile together as a unit.

Submachine Gun

A machine gun that fires pistol caliber rounds such as .45 acp or 9mm Luger (Parabellum)

Long Recoil

A semi-automatic pistol in which the barrel and breechblock are locked together for the full distance of rearward recoil travel, after which the barrel returns forward, while the breechblock is held back. After the barrel has fully returned, the breechblock is released to fly forward, chambering a fresh round in the process.

Over Travel

If the trigger is able to continue moving to the rear after the shot has fired, the trigger is said to over-travel.

Pitch

The angle of the butt of a gun in relation to the line of sight. Pitch is measured by resting the gun with its butt flat on a floor, the top of the receiver against a wall and its muzzle pointing up. The distance of the muzzle from the wall is the gun's pitch down.

Zero

A firearm is said to be "zeroed in" when its sights have been adjusted so that the bullet will hit the center of the target when the sights are properly aligned upon the center of the target. The farthest distance from a firearm at which the bullet's path and the point of aim coincide. This term is also used to mean the process of insuring that the sights of a firearm are properly aligned so that where they indicate the bullet will strike is in fact where it strikes.

Riding the Slide

Racking the slide incorrectly by allowing your hand to rest upon the slide as it moves forward during the loading procedure. Riding the slide is a common cause of misfeeds and other malfunctions.

Loaded

A firearm is loaded when a cartridge is in its firing chamber. However, for safety reasons all firearms are always treated as loaded at all times.

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Point Blank Range

The farthest distance that a target of a given size can be hit without holding over or under with the sights. The exact range is determined by the performance of the cartridge used, the ZERO range, and the accepted size of the target area. This term is not to be confused with point blank shooting.

Delayed Blowback

A self-loading firearm whose breechblock and barrel are not positively locked together, but which incorporates a mechanism which initially restricts the breechblock from moving when fired, delaying its opening.

Brick

A box of ammunition roughly equal in size and weight to a brick. Most often used to describe a 500-round container of .22 Long Rifle ammunition.

Firing Line

A line, either imaginary or marked, from which people shoot their firearms down range.

Throat Erosion

The wearing of the portion of the barrel where the gas pressure and heat is highest as the projectile leaves the chamber. The greater the chamber pressure the more rapid throat erosion occurs which is compounded by rapid firing which heats and weakens the steel.

Battery

Most firearms do not have literal batteries. But a firearm is said to be in battery when the breech is fully closed and locked, ready to fire. When the breech is open or unlocked, the gun is out of battery and no attempt should be made to fire it. A semi-automatic is out of battery when the slide fails to come all the way forward again after the gun has fired, making it dangerous or impossible to fire the next round. This condition can be created by a misfeed, a dirty gun, weak springs, the shooter's thumbs brushing against the slide, riding the slide, or any of several other causes.