Letter R

The Definition of Rolling Block

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Rolling Block

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.


19 Other Firearms Definitions You Need To Know


Slide Bite

A phenomenon which is often grouped with hammer bite. In this case the web of the shooting hand is cut or abraded by the rearward motion of the semi-automatic pistol's slide, not by the gun's hammer. This most often occurs with small pistols like the Walther PPK and Walther TPH that have an abbreviated grip tang. This problem is exacerbated by the sharp machining found on many firearms.

Trigger Slap

An uncomfortable sensation caused by the trigger springing back into the shooter's trigger finger while firing.

Scope Blocks

A pair of small dovetailed steel bases, screwed usually one to the barrel and one to the front receiver ring of a rifle, to accept mounts for target scopes such as the Unertl where the scope is allowed to move forward in the rings under the recoil of the rifle and which typically carry the windage and elevation adjustments in the mount.

JSP

Abbreviation for jacketed soft point

Overbore Ammunition

Small caliber bullets being used in large cases. E.g. .22 bullet in a .45 acp case.

Semi-Wadcutter

A bullet design featuring a conical extended nose, with a flat point, and a sharp edged shoulder that serves to cut a full diameter hole in the target. This design also may be found with a hollow point to facilitate expansion. A modified wadcutter bullet design with slightly sloping edges, designed to load smoothly in a semi-automatic pistol.

Machine Gun

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

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

Parabellum

Latin word meaning "for war." It is actually the proper name of the semiautomatic pistol commonly known in the USA as the "Luger. Because of that pistol and the ammunition created for it, the common 9mm cartridge used nowadays is also known as 9mm Parabellum or 9mm Luger."

Bolt

The mechanism of some firearms that holds the cartridge in place during the firing process. It must be moved out of the way to load and unload the gun; this action may be manually performed by the shooter pulling back on an exterior knob called the bolt handle and then sending it forward again, or the action may be performed by other moving parts within the firearm. When the user must move the bolt manually, the firearm is called a bolt-action firearm.

CCW

Abbreviation for Concealed Carry Weapon

Casket Magazine

A quad stack box magazine.

Trigger Jerk

Yanking the trigger back abruptly, thus pulling the muzzle of the gun downward at the moment the shot fires.

Trigger Guard

Usually a circular or oval band of metal, horn or plastic that goes around the trigger to provide both protection and safety in shooting circumstances. The shooter's finger should never be within the trigger guard unless the sights are on target and the shooter has made the decision to fire.

Wheel-Lock

An early firearm mechanism in which a wheel with serrated edges is wound against the tension of a strong spring and spins against a piece of iron pyrite, sending a shower of sparks into the pan to ignite the charge.

Cross Dominant

This means a shooter who is right-handed but left-eyed, or left-handed and right-eyed.

Cartouche

A mark within a border, typically stamped into the wood, especially of an American military rifle. It shows the initials of the name of the accepting inspector and often, the date he accepted the firearm into service.

Matched Pair

Two firearms that are manufactured identical in every way and are sequentially serial numbered and are sold as a set. The most common type of matched pair guns are cowboy style revolvers for a couple of reasons, both guns will feel exactly the same in the hands and they make the set more collectable.

Sear

The part of the trigger mechanism which holds the hammer or striker back. Pressure on the trigger causes the sear to release the hammer or striker, allowing it to strike the firing pin and discharge the weapon.