Letter P

The Definition of Parallax

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Parallax

This occurs in telescopic sights when the primary image of the objective lens does not coincide with the reticle.Telescopic sights often have parallax adjustments to minimize this effect.


19 Other Firearms Definitions You Need To Know


LR

Abbreviation for Long Rifle. Typically used in the .22 caliber cartridge designation .22LR. However can be used as an abbreviation for Kentucky Long Rifle

Trigger Lock

A locking device, usially a clable with a padlock that you put on a firearm to render it unable to be fired buy running it through the magazine well and out the ejection port.

Half grip

Round knob, semi pistol grip.

Hand-Detachable Locks

The firing mechanism of a break-open gun which may be removed for inspection or cleaning without the use of tools. The release latch may be plainly visible or concealed. A feature typically seen on sidelock guns but also on the Westley Richards "droplock" boxlock action.

Negligent Discharge

The unplanned discharge of a firearm caused by a failure to observe the basic safety rules, not a mechanical failure of the gun.

Standing Breech

The face of the action of a break-open firearm which houses the firing pins and receives the direct recoil of the fired round.

Dry Fire

To pull the trigger and release the hammer of a firearm without having a cartridge in the chamber.

Forend

One of the three major dismountable components of a break-open gun (the others being the barrel(s) and the action/buttstock) which secures the barrels to the receiver, often houses the ejector mechanism, and for some, provides a handle for the one's secondary hand.

Receiver Ring

The portion of the receiver which is threaded so the barrel can be attached to it.

Point of Aim

The point at which you are aiming the firearm at.

Open Sights

A common type of iron sights in which the rear sight is an open-topped U or a V or a square-notch shape and with a blade type front sight, in contrast to the closed circle commonly found in aperture sights.

Machine Gun

A fully automatic firearm that rapidly fires multiple rifle-caliber shots with a single pull of the trigger.

Terminal Ballistics

A sub-field of ballistics, is the study of the behavior of a projectile when it hits its target.

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.

Traditional Isosceles

In the Traditional Isosceles stance, Both arms are stretched almost equally forward with the gun centered forward. The knees are straight or only slightly flexed, and the entire body is upright and parallel to the target. This is an acceptable range stance provided recoil control is not an issue and you don't need to make rapid follow-up shots. However, if you are practicing for self-defense, you will probably want to use the Modern Isosceles stance stance instead.

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.

Crane

A swing-out arm on a revolver, to which the cylinder is mounted when opened facilitates loading and cleaning.

Chamber

The rear portion of the barrel or firing cylinder in which the cartridge is inserted prior to being fired. Rifles and pistols generally have a single chamber in their barrels, while revolvers have multiple chambers in their cylinders and no chamber in their barrel.

Heel & Toe Plates

Protective plates, usually of steel or horn, covering the top and bottom of a gunstock's butt only (the heel and the toe); leaving wood exposed in the center