Letter Z

The Definition of Zero

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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.


19 Other Firearms Definitions You Need To Know


Side-By-Side

A shotgun with two barrels which are situated next to each other. Somtimes also abreviated as SxS.

Ball

Originally used to describe the spherical projectile used in black powder firearms, now also used to refer to a fully jacketed bullet of cylindrical profile capped with a round nose

Heel

The top of the butt-end of a gun stock.

Gape

The degree to which the barrel(s) of a break-open gun drop down; the size of the opening space, which should be sufficient to allow for ease of loading, unloading and properly-functioning ejection. A good gape is easier to achieve on a side-by-side than an over & under where the bottom barrel is well-enclosed by the action body.

Riot Gun

A popular term for a short barreled repeating shotgun as frequently used in law enforcement and personal protection.

Safety

A device, incorporated into the design of most firearms actions that, when engaged, should prevent the discharge of the firearm. Some safeties are more positive than others. A safety device is not a perfect substitute for the general principles of responsible gun handling. Never point a gun in a direction you do not intend to shoot

POI

Abbreviation for Point of Impact

Bayonet Lug

A mounting point on a small arm that allows a bayonet or other accessory to be attached.

Quadrail

Sometimes spelled Quad Rail. First conceived and sold by Knights Armament Company in the mid 90s when Reed Knight saw soldiers duct taping flashlights to their handguards in news footage of Panama, the quad rail has become almost a standard item found on most military rifles. Quad rails allow easy attachment of accessories which aid tactical shooters, such as lights, infrared lasers, foregrips, sling attachment points, and secondary sighting systems. However, nowadays, any full length forearms on an AR, with or without rails may also be refered to as a Quadrail.

Half grip

Round knob, semi pistol grip.

Passive Safety

Any safety, internal or external, which functions apart from the shooter's conscious control. Grip safeties are one example of a passive external safety.

Falling Block

A type of action used primarily for single shot rifles whereby some kind of lever actuates a breechblock, moving it downwards in a vertical recess to expose the chamber. May have visible or enclosed hammer. For any given barrel length, it allows a shorter overall rifle length compared to a bolt action because no space is taken up by the forward-and-back cycling of the bolt. Most of the better British makers produced them in limited numbers around the turn of the last century, the Farquharson being the most iconic. Perhaps the best-known falling block action today is the Ruger No.1.

Cylindro Conoidal Bullet

A hollow base bullet, shaped so that, when fired, the bullet will expand and seal the bore. It was invented by Captain John Norton of the British 34th Regiment in 1832, after he examined the blow pipe arrows used by the natives in India and found that their base was formed of elastic locus pith, which by its expansion against the inner surface of the blow pipe prevented the escape of air past it.

Spray and Pray

A term often used to refer to the very poor and dangerous practice of rapidly firing many shots at a target as possible in the hope that one or more may hit the target. This practice is a danger not only to bystanders but also to the shooter.

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.

Spotter

The spotter is a helper who gives the shooter guidance on how to hit a particular target. In some cases the spotter may just report the location of the bullet impact. In other cases they may judge the speed and direction of the wind, determine the range, and give the shooter the settings to be used on the sights.

Monte Carlo Stock

A rifle or shotgun stock that has a Monte Carlo style comb

Cartridge Overall Length

This is the maximum overall length the cartridge can be (and is expected to be) in order to function properly in magazines and the mag well of a bolt action rifle.

Four Rules

The four rules of firearms safety,were originally introduced in the early 1900's by various shooting education sources (with varying phrasing, but same implications), they apply every single time a firearm is handled in any way or for any reason. The NRA teaches the Three Rules of Safe Gun Handling.

Rule One: All guns are always loaded. (Treat all guns as if they are loaded, no matter what!)
Rule Two: Never point your firearm at anything you are not willing to destroy.
Rule Three: Never put your finger on the trigger unless your sights are on target (and you have made the decision to fire).
Rule Four: Be sure of your target and what is behind it.