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


Derringer

A small single-shot or multi-barreled pocket pistol. Derringers (spelled with two Rs) are called that because of the original desinger and anmufactuturer of that type of gun, Henry Deringer. To get around copyright infringment other designers and manufacturers spell the name with two Rs.

Slide Release

A slang term for slide catch.

Optical Sight

Usually a telescopic firearm sight.

Drum Magazine

A type of firearms magazine that is cylindrical in shape, similar to a drum. Probably the most recognizable drum magazine is the magazine for a Thompson carbine rifle, also known as the Tommy Gun.

Breech Pressure

The amount of rearward force exerted by the propellant gases on the bolt or breech of a firearm action or breech when a projectile is fired. The applied force has both magnitude and direction, making it a vector quantity. This is also known as Bolt Thrust on firearms that are Bolt Action

Laser Sight

A laser sight is an alternative sighting device which enables the shooter to quickly and accurately see where the firearm is aimed even when lighting or other conditions prevent using the gun's normal sights. Lasers may be located within the grips, hung from accessory rails at the front end of the gun, or placed within the firearm.

Submachine Gun

A fully automatic firearm that fires pistol ammunition.

Bullpup

A firearm configuration where the magazine and action are behind the trigger.

Detonate

To explode with great violence. It is generally associated with high explosives e.g. TNT, dynamite, etc., and not with the relatively slow-burning smokeless gunpowders that are classed as propellants.

Pattern

A shotgun term which refers to the manner in which the pellets spread out as they exit the gun. "The pattern" refers to the overall shape of the entire set. A tight pattern is one in which the pellets are closely grouped when they land on target. A loose pattern is one in which the pellets are widely spread.

Combination Gun

A shoulder-held firearm that has two barrels; one rifle barrel and one shotgun barrel. Most combination guns are of an over/under design (abbreviated as O/U), in which the two barrels are stacked vertically on top of each other, but some combination guns are of a side-by-side design (abbreviated as SxS), in which the two barrels sit beside each other.

Flintlock

A system of firearms ignition, in general use circa 1660 - 1825, whereby the pull of a trigger releases a sear from a notch in a spring-loaded hammer, which holding a properly knapped piece of flint, strikes a vertical slab of steel (called a frizzen) scraping off tiny molten particles of the steel, and pushing it forward causes an integral flashpan cover to open forward, exposing a bit of fine gunpowder below, which when contacted by the falling sparks, ignites and sends a flash of fire through the touchhole, into the loaded breech setting off the main charge and firing the gun. The Flintlock system was supplanted by the Percussion system around 1820.

Blowback

A semi-automatic firearm whose breechblock and barrel are not mechanically locked together when fired. In such case the breechblock immediately begins to separate from the barrel upon firing. Blowback is used in comparatively low powered weapons, in which inertia of the breechblock, and cartridge wall adhesion against the chamber, are sufficient enough to retard opening until breech gas pressures have fallen to a safe level.

Compensator

Also call a Muzzle Brake. A device attached to or made as part of a firearms barrel designed to reduce recoil or muzzle movement on firing. They generally increase muzzle blast.

Brady Law

Brady Handgun Violence Prevention Act of 1993. The Brady Handgun Violence Prevention Act of 1993 mandates background checks of gun buyers in order to prevent sales to people prohibited under the Gun Control Act of 1968 legislation. Requires checks to be performed through the FBI's National Instant Criminal Background Check System (NICS). Records of who has been checked are not preserved because federal law prohibits the creation of a national registry of gun ownership. Sales by unlicensed private sellers who are not engaged in gun dealing as a business are not subject to the checks under federal law, though they are required by some states.

Parkerizing

A chemical phosphate process developed during the second world war to provide an economical, durable and non-reflective surface finish to military firearms.

Point of Impact

The point where the projectile from a firearm hits.

CHL

Abbreviation for Concealed Handgun License.

Drift

The departure of a bullet or shot charge from the normal line of flight. This can be caused by wind or the unbalanced spinning of the bullet.