The Definition of Sectional Density
The relationship between a bullet's weight and its diameter. A long bullet, such as the original 7.62x54R
loading for the Mosin Nagant 91/30, will have a high sectional density and consequently greater
penetration than a shorter bullet of similar construction. A shorter bullet with less sectional
density will have relatively less penetration, but greater knockdown power.
19 Other Firearms Definitions You Need To Know
The length, within a rifled barrel, required to accomplish one full rotation. 1:12 Twist, means a bullet passing down the bore would complete one revolution in twelve inches.
1:7 Twist, means a bullet passing down the bore would complete one revolution in seven inches, which makes it a tighter twist than 1:12.
Different weights of bullet require appropriate rates of twist.
Markings impressed into the base of a cartridge case, normally identifying the maker's name, the cartridge calibre designation, and sometimes the date.
Recoil operation is an operating mechanism used in locked-breech, autoloading firearms. As the name implies, these actions use the force of recoil to provide energy to cycle the action.
Visible disturbance in the air by a bullet. Typically this takes the form of image distortion that persists for a fraction of a second in the shape of an inverted V similar to that of a boat wake.
A bore snake is a tool used to clean the inside (bore) of the barrel of a gun. It resembles a short section of rope with a smaller,
weighted cord attached to one end to help feed the bore snake through the barrel. A bore snake often has one or more integrated brushes to help clean the barrel,
and may also be used to apply lubricant. It is an alternative to using a cleaning rod and patches to clean the barrel of a gun.
Bore snakes are made in different sizes for different calibers and gauges of guns.
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.
A slang term for a shotgun.
A Federal Firearms License (FFL) is a license in the United States that enables an individual or a company to engage in a business pertaining to
the manufacture of firearms and ammunition or the interstate and intrastate sale of firearms. Holding an FFL to engage in certain such activities has
been a legal requirement within the United States since the enactment of the Gun Control Act of 1968.
A description of a bullet whose forward diameter has expanded after penetration.
A tip for a cleaning rod, a jag, with spirally-radial wires for vigorously scrubbing a gun's bore.
Ammunition that has been assembled by a commercial vendor of ammunition and sold in retail stores. This is as opposed to Hand loads which have been assembled by individuals and are not typically sold.
Abbreviation for Long Rifle. Typically used in the .22 caliber cartridge designation .22LR. However can be used as an abbreviation for Kentucky Long Rifle
An optical sight, offering some magnification, often variable, with some kind of adjustable aiming grid inside (a reticle),
which when mounted on a firearm, usually a rifle, makes sighting easier.
A magnifying tube through which the shooter may see the target and aim the firearm. Scopes contain a reticle, commonly in the shape of a cross, which must be properly centered upon the target for accurate aim.