Letter M

The Definition of Minute Of Angle

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Minute Of Angle

A 1/60th part of a degree, the unit of measure used in adjusting rifle sights. As it turns out conveniently, a minute of angle translates almost exactly to one inch at 100 yards (actually 1.047 inches), to two inches at 200 yards and three inches at 300 yards


19 Other Firearms Definitions You Need To Know


Cast Off

An offset of a gun stock to the right, so that the line of sight aligns comfortably with the right eye while the butt of the stock rests comfortably on the right shoulder. Almost all right-handed shooters benefit from a little castoff and most custom built guns are made this way. The only question is how much. The castoff of a gun is about right when, with the gun comfortably mounted, the front bead lines up with the center of the standing breech.
A stock offset to the left, for shooting from the left shoulder is said to be

Double-Set Trigger

Usually only found on black powder muzzle loading rifles and pistols, pulling the rear (set) trigger converts the front (main) trigger to a light, hair trigger (too light and sensitive to be carried safely in the field). While the front trigger is always at the ready, if one has the time, using the set trigger feature may allow for a more accurate long-distance shot. Operates using its own miniature firing mechanism (sear, spring and hammer) when cocked, to multiply the force of a pull on the main trigger.

Inertia Firing Pin

A firing pin which moves freely forward and backward in the breechblock.

Carbine

A rifle with a relatively short barrel.

Deringer

The original small single-shot or multi-barreled pocket pistol designed and manufactured by Henry Deringer of Philadelphia. 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. However guns designed and built by Deringer are spelled with only one R

Shooting Sports

There are a lot of different competitions and other games which involve firearms. These are all referred to collectively as the shooting sports.

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.

Crosshairs

The cross-shaped object seen in the center of a firearm scope. Its more-proper name is reticle.

Neck

The forward portion of a bottlenecked cartridge case. Also the portion of a rifle chamber in which the neck of the cartridge case rests.

External Safety

A safety lever or button found on the outer surfaces of the firearm and is accessible to the user. Enabling the external safety should prevent accidental pulling of the trigger. However, the best safety is always you.

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

Key Fastener

A horizontal wedge, press-fit through the forend of a vintage gun, through a lump attached to the underside of the barrel and out the other side of the forend. To secure the forend in position. Also called a crosspin or a wedge fastener.

Breech

The rear end of the barrel into which the cartridge is inserted

AR

Contrary to some people's belief, AR does NOT stand for Assault Rifle. The designation AR stands for the original designing company ArmaLite.
An AR is a firearm platform originally designed by ArmaLite and built by Colt, an AR is a lightweight, intermediate cartridge magazine-fed, air-cooled rifle with a rotating lock bolt, actuated by direct impingement gas operation or long/short stroke piston operation. It has been produced in many different versions, including numerous semi-automatic and selective fire variants. It is manufactured with extensive use of aluminum alloys and synthetic materials. Types of ARs include AR-15, AR-10 and AR-7.

Charger

A device typically made from stamped metal which holds a group of cartridges for easy and virtually simultaneous loading into the fixed magazine of a firearm.

DST

Abbreviation for Double-Set Trigger

Flashbang (holster)

A flashbang holster is a type of holster for women that allows the firearm to sit horizontally tucked under the bra band. As the gun is pulled straight down, the clamshell opens up and permits the wearer to draw. It is named a flashbang because the wearer hash to pull up their shirt (flash) to draw the gun out of the holster, then shoot (bang). These holsters have become very popular with women that conceal carry since the firearms is neatly hidden under the breast line in clothing and does not require the wearer to stay latched onto a purse or have to deal with the inconviences that come with inside the waist band carry

Back Action

A sidelock action where the mainspring is mounted rearward towards the butt. The back action is often used in double rifles where the need for strength requires as little steel as possible be removed from the bar of the action.

Hood

Front sight hood. A hollow cylinder fitted to a rifle's front sight ramp, both to protect the delicate front sight bead from impact, and to shade it from oblique sunlight which could have the effect of altering the sight's apparent position.