Letter Y

The Definition of Yaw

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The heading of a bullet, used in external ballistics that refers to how the Magnus effect causes bullets to move out of a straight line based on their spin.

19 Other Firearms Definitions You Need To Know

Back Bored

A shotgun barrel that has a bore diameter increased beyond standard specifications, but less than the SAAMI maximum. Done in an attempt to reduce felt recoil, improve patterning, or change the balance of the shotgun.

Second Amendment

The second article in the United States Bill of Rights which states, "A well regulated militia being necessary for a free state, the right of the people to keep and bear arms shall not be infringed."


A unit of measure traditionally used for black powder shotgun charges. Today, used for smokeless powders on the basis of the new propellant's equivalent performance to that weight of black powder. Thus, a shotgun shell marked 3 - 1 1/8 would be loaded with the smokeless powder equivalent of 3 drams of black powder, and with 1 ounce of shot. 1 Dram = 1/16 ounce = 437.5 grains.


The part of a revolver's frame connecting the recoil shield to the barrel-mounting recess; adding considerable strength compared to that of early black powder Colt revolvers, and providing a base for a rear sight.


The process of assembling cartridge case, bullet or shot, wads and primer to produce a complete cartridge with the use of hand tools in the interest of loading for firearms for which cartridges are not available, experimenting with loads to achieve better performance, or to save money. Not to be attempted without knowledgeable instruction and careful study of the process.

Scout Rifle

A concept created by eminent gun writer Col. Jeff Cooper. A scout rifle, generally, is a bolt action carbine firing a medium power round suitable for taking large game (e.g., .308), fitted with a long eye-relief telescopic sight mounted on the barrel, and a back up set of iron sights.

Mercury 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't hurt either.

Saddle Ring

A steel ring, around an inch in diameter, mounted to a stud, usually on the left side of the receiver of a carbine, to which may be tied a leather thong to secure it to a saddle or a scabbard so as not to lose the carbine when riding a rambunctious horse.

Ear Plugs

Hearing protection that fits inside the ear canal.

Touch Hole

A small orifice at the breech end of the barrel of a muzzle-loading firearm through which the exploding priming charge is conducted from the flash pan to the main charge.

Straddle Floorplate

A hinged plate covering the bottom of a rifle magazine and extending rearward on either side of the triggerguard. This design allows it to be more securely fastened for one more imperceptible step towards total reliability.


A bullet that is designed to disintegrate into tiny particles upon impact to minimize their penetration for reasons of range safety, to limit environmental impact, or to limit the danger behind the intended target. Examples are the Glaser Safety Slug and the breaching round.


The portion of the stock (on a rifle) or frame (on a pistol) gripped by the trigger hand.


A person who can shoot up to the mechanical capability of their weapon.


Helical grooves in the barrel of a gun or firearm, which imparts a spin to a projectile around its long axis. This spin serves to gyroscopically stabilize the projectile, improving its aerodynamic stability and accuracy.


The lock that preceded the 'true' flintlock in both rifles and pistols in the 17th century. Commonly used throughout Europe in the 1600s, it gained popular favor in the British and Dutch military. A doglock carbine was the principal weapon of the harquebusier, the most numerous type of cavalry in the armies of Thirty Years War and the English Civil War era.


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.

High Kneeling

A shooting position in which one or both knees are touching the ground, but the shooter is otherwise erect.

Magazine Pouch

Commonly shortened to mag pouch, this is a device to hold extra magazines which fastens to the shooter's belt.