Gun safety is the study and practice of managing risk when using, transporting, storing and disposing of firearms, airguns and ammunition in order to avoid injury, illness or death.
A cartridge, also known as a round, is a type of pre-assembled firearm ammunition packaging a projectile, a propellant substance and an ignition device (primer) within a metallic, paper, or plastic case that is precisely made to fit within the barrel chamber of a breechloading gun, for convenient transportation and handling during shooting. Although in popular usage the term "bullet" is often used to refer to a complete cartridge, the correct usage only refers to the projectile.
In firearms terminology, an action is the functional mechanism of a breech-loading firearm that handles the ammunition cartridges, or the method by which that mechanism works. Actions are technically not present on muzzleloaders, as all those are single-shot firearms with a closed off breech with the powder and projectile manually loaded from the muzzle. Instead, the muzzleloader ignition mechanism is referred to as the lock.
A semi-automatic pistol is a handgun that automatically ejects and loads cartridges in its chamber after every shot fired. Only one round of ammunition is fired each time the trigger is pulled, as the pistol's fire control group disconnects the trigger mechanism from the firing pin/striker until the trigger has been released and reset.
The slide on the majority of fully/semi-automatic pistols is the upper part that reciprocates ("slides") with recoil during the gun's operating cycle. It serves as the bolt carrier group (BCG) and partly as the receiver, and generally houses the firing pin/striker, the extractor and frequently also the barrel, and provides a mounting platform for iron and optical sights.
In firearms, headspace is the distance measured from a closed chamber's breech face to the chamber feature that limits the insertion depth of a cartridge placed in it. Used as a verb by firearms designers, headspacing refers to the act of stopping deeper cartridge insertion. The exact part of the cartridge that seats against the limiting chamber feature differs among cartridge and gun designs. In general, bottleneck rifle cartridges headspace on their case shoulders; rimmed cartridges headspace on the forward surfaces of their case rims; and rimless pistol cartridges headspace on their case mouths. The case belts on belted cartridges were originally added to allow headspacing on the belt's forward surface, But in practice, this is often vestigial, and rifles chambered for belted cartridges may well headspace them on their shoulders and still be within CIP or SAAMI dimensional limits. However, belted cartridges and their corresponding chambers at their nominal CIP or SAAMI dimensions will headspace on the belt.
A firearm is said to fire from an open bolt or open breech if, when ready to fire, the bolt and working parts are held to the rear of the receiver, with no round in the chamber. When the trigger is actuated, the bolt travels forward, feeds a cartridge from the magazine or belt into the chamber, and fires that cartridge in the same movement. Like any other self-loading design, the action is cycled by the energy released from the propellant, which sends the bolt back to the rear, compressing the mainspring in readiness for firing the next round. In an open-bolt gun firing semi-automatically, the bolt is caught and held at this point by the sear after each shot; and in automatic open-bolt fire, it's caught and held in this manner whenever the trigger is released. In contrast to this, in closed-bolt guns, the trigger and sear do not affect the movement of the bolt directly.
Blowback is a system of operation for self-loading firearms that obtains energy from the motion of the cartridge case as it is pushed to the rear by expanding gas created by the ignition of the propellant charge.
In breechloading firearms, an extractor is an action component that serves to remove spent casings of previously fired cartridges from the chamber, in order to vacate the chamber for loading a fresh round of ammunition.
Tap, rack, bang (TRB) or tap, rack, and go (TRG) is jargon for the response to a failure to fire in a firearm with a removable magazine. This is designated as an "Immediate Action" and involves no investigation of the cause, but is effective for common failures, such as defective or improperly seated ammunition magazines.
- Tap – to tap the magazine. This is to ensure that the magazine is properly/completely inserted in the firearm so that it feeds properly. As typically taught in tactical firearms courses, the "tap" is applying pressure on the floor plate of the magazine to lock it into place. It does not constitute 'smacking' the magazine, as this can irreversibly damage the magazine's lip.
- Rack – pull back sharply and then quickly release the cocking handle/slide of the firearm. This will eject a misfired round, which could be a possible cause of the stoppage, and to chamber the next round.
- Bang/Go – aiming and firing the firearm again. If the firearm again does not fire or fails to extract the spent round, it may indicate a more serious problem with the firearm, requiring maintenance. For instance, if the firing pin is too lightly striking the primer on a cartridge, it may indicate a worn-out spring or firing pin.
A snap cap is a firearm accessory device shaped like a standard cartridge/shotshell but contains no functional components, namely the primer, propellant (gunpowder) and projectile. It serves the same purpose as a dummy round, but different in that a dummy is usually modified from a real cartridge with its propellant and primer removed, while a snap cap has a monolithic outer shell and is specifically designed to be a fake cartridge from the very beginning.
A slamfire is a discharge of a firearm occurring as a cartridge is being loaded into the chamber. Some firearms are designed to slamfire, but the term also describes a malfunction of self-loading firearms. Shooters accustomed to firearms requiring trigger activation for discharge may be unprepared for a slamfire discharge.
The Colt Model 1900 is a short-recoil operated "self-loading", or semi-automatic .38 caliber handgun introduced by Colt's Manufacturing Company at the turn of the 20th century. The M1900 was the first firearm to be chambered in .38 ACP and was the first handgun to utilize short-recoil operation.
Limp wristing is a phenomenon commonly encountered by semi-automatic pistol shooters, where the shooter's grip is not firm enough and the wrist is not held firm/straight enough to keep the frame of the firearm from traveling rearward while the bolt or slide of the firearm cycles. This condition often results in a failure to complete the operating cycle, properly termed a malfunction, but commonly termed a "jam". This phenomenon can affect metal or poly framed firearms equally. Both semi-automatic rifles and semi-automatic shotguns, if fired without the stock held against the shoulder correctly, may also be prone to limp wristing. Of the important variables involved in this type of malfunction, bullet and gas momentum, slide and barrel mass, recoil spring pre-load and spring rate, and shooting hand and arm mass are much more important than the compliance (limpness) of the wrist.
The cocking handle, also known as charging handle or bolt handle, is a device on a firearm which, when manipulated, results in the bolt being pulled to the rear, putting the hammer/striker into a spring-loaded ("cocked") "ready and set" position, allowing the operator to open the breech and eject any spent/unwanted cartridge/shell from the chamber, and then load a new round from the magazine or belt if required. By opening the breech, it also helps the operator to verify that the weapon's chamber is clear of any rounds or other obstructions; to clear a stoppage such as a jam, double-feed, stovepipe or misfire; to facilitate moving the bolt back into battery, acting as a forward assist ; and to release a bolt locked to the rear by a catching mechanism on a firearm equipped with a "last round bolt hold open" (LRBHO) feature.
Out-of-battery refers to the status of a firearm before the action has returned to the normal firing position.
A squib load, also known as a squib round, pop and no kick, or just a squib, is a firearm malfunction in which a fired projectile does not have enough force behind it to exit the barrel, and thus becomes stuck. This type of malfunction can be extremely dangerous, as failing to notice that the projectile has become stuck in the barrel may result in another round being fired directly into the obstructed barrel, resulting in a catastrophic failure of the weapon's structural integrity.
The following are terms related to firearms and ammunition topics.
In firearms, a safety or safety catch is a mechanism used to help prevent the accidental discharge of a firearm, helping to ensure safer handling.
Push feed and controlled feed are two main types of mechanisms used in firearms to describe how the bolt drives the cartridge into the chamber and extracts the spent casing after firing.
