Letter P

The Definition of Penetration

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Penetration

The distance travelled by a projectile from the point where it strikes the target to the point where it stops.


19 Other Firearms Definitions You Need To Know


Island Rear Sight

A rear barrel sight base, more articulated than having the sight simply dovetailed into the barrel, but not requiring as much gunsmithing as having it mounted onto a proper quarter-rib.

Backstop

Anything that will safely stop a bullet and prevent it from hitting anything else after the target is struck.

Blank

A type of cartridge for a firearm that contains gunpowder but no bullet or shot. When fired, the blank makes a flash and an explosive sound (report). Blanks are often used for simulation (such as in historical reenactments, theatre and movie special effects), training, and for signaling (see starting pistol). Blank cartridges differ from dummy cartridges and snap caps, which are used for training or function testing firearms; these contain no primer or gunpowder, and are inert.

Saturday Night Special

A slang term for a small inexpensive handgun. Saturday night specials have been defined as compact, inexpensive, small-caliber handguns with perceived low quality; however, there is no official definition of "Saturday night special" under federal law, though some states define "Saturday night specials" or "junk guns" by means of composition or materials strength. Low cost and high availability make these weapons attractive to many buyers despite their shortcomings.

Terminal Ballistics

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

Anson & Deeley Action

A type of internal hammer side by side shotgun boxlock action. It was patented in 1875 and is the essence of simplicity utilizing only two springs and three moving parts (per barrel). One of the most successful action designs ever, and still produced to this day by most SxS shotgun manufacturers.

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.

Recoil Compensator

A device fitted inside the buttstock of a heavily-recoiling gun or rifle, usually containing mercury and a valve. As the gun recoils, the mercury is displaced temporarily, increasing the duration, and thus diminishing the perceived impact of the recoil. The added half-pound of weight doesn#39;t hurt either.

Electronic Hearing Protection

Ear muff or ear plug hearing protection that have internal electronics that amplify human voices while excluding all noises louder than a given decibel rating. Electronic hearing protection is best used when shooting outdoors. When on an indoor range they have a tendency to pick up too much echo and other muffled sounds.

Ricochet

A rebound, bounce or skip off a surface, particularly in the case of a projectile.

Trigger Pull Weight

The ammount pressure needed (measured in pounds) for the trigger finger must put on the trigger before the gun will fire. Trigger pull weight is measured by the number of pounds and ounces of pressure required to pull the trigger past the break.

Battery

Most firearms do not have literal batteries. But a firearm is said to be in battery when the breech is fully closed and locked, ready to fire. When the breech is open or unlocked, the gun is out of battery and no attempt should be made to fire it. A semi-automatic is out of battery when the slide fails to come all the way forward again after the gun has fired, making it dangerous or impossible to fire the next round. This condition can be created by a misfeed, a dirty gun, weak springs, the shooter's thumbs brushing against the slide, riding the slide, or any of several other causes.

Twilight Sight

A rifle front sight with a extra-large, folding bead. Typically, in addition to the normal fine bead (which allows for more precision) the larger bead, while at a cost of potential accuracy, is more readily acquired in marginal light. Also called a Gloaming sight

Rail

A feature on some guns which allows various aftermarket accessories to be attached the firearm such as flashlights or lasers. On pistols, if equipped, the rail is on the underside of the frame below the barrel. On rifles, a rain can be found above or below the barrel, with AR type rifles, the forestock can be made of rails allowing all kinds of attachments in various positions.

Electronic Firing

The use of an electric current to fire a cartridge, instead of a percussion cap. In an electronic-fired firearm an electric current is used instead to ignite the propellant, which fires the cartridge as soon as the trigger is pulled.

Upset Forging

A process that increases the diameter of a workpiece by compressing its length.

Misfeed

Is a failure of the next round to completely enter the chamber. Misfeeds and failures to feed are very similar, a failure to feed is a round that never even leaves the top of the magazine, while a misfeed is a round that leaves the magazine but does not enter the chamber.

Ramrod

A long, slender, dowel-like tool used to force powder and shot down the bore of a muzzle-loading firearm. For hand-fired guns, normally retained in some kind of receptacle attached to the gun's barrel. Carried separately for muzzle-loading cannon.

Disc-Set Strikers

Circular steel fittings, about 1/2 inch in diameter, screwed into the breech face of a gun and through which the firing pins pass. Firing pin bushings allow the convenient replacement of broken firing pins. They also allow the renewal of an older gun where, over the decades, leakage of high-pressure gas from corrosive primers has eroded the breech face around the firing pins; and replacing these bushings with new ones, slightly oversized can compensate for a situation where proper headspace has been compromised.