Letter U

The Definition of Underbolts

Arsenal Exchange - Firearms Classifieds - Industry Directory

Underbolts

A sliding bar, running longitudinally through the watertable of a break-open side-by-side gun's action, with openings through which the lumps of the barrels pass when the gun is closed. Under spring tension, this bar moves forward when the opening control is released and its two locking surfaces engage complementary slots (bites) in the rear of the two barrel lumps. Originally operated by a hinged tab in front of the trigger guard. Now invariably operated by a cam from Scott's [toplever] spindle. Most modern side-by-side guns lock closed in this manner.


19 Other Firearms Definitions You Need To Know


Trigger Pull

The entire process of moving the trigger from its forward-most position to its rearward-most position, causing the hammer to fall and the shot to fire.

Pellet (shotgun)

Small spherical projectiles loaded in shotshells and more often called "shot."

Mauser Action

The premier bolt action, whose design by Paul Mauser coalesced in 1898, and from which were derived the Springfield 1903, the Winchester Model 70 and many others.

Bluing

Also spelled blueing. A passivation process in which steel is partially protected against rust, and is named after the blue-black appearance of the resulting protective finish. True gun bluing is an electrochemical conversion coating resulting from an oxidizing chemical reaction with iron on the surface selectively forming magnetite (Fe3O4), the black oxide of iron, which occupies the same volume as metallic iron. Bluing is most commonly used by gun manufacturers, gunsmiths and gun owners to improve the cosmetic appearance of, and provide a measure of corrosion resistance to, their firearms.

Doughnut Pattern

A shotgun pattern with a hole in the middle generally caused by the interference of the top wad.

Submachine Gun

A fully automatic firearm that fires pistol ammunition.

Boresight (Bore Sight)

Crude adjustments made to an optical firearm sight, or iron sights, to align the firearm barrel and sights. This method is usually used to pre-align the sights, which makes zeroing (zero drop at XX distance) much faster.

Stance

How the shooter positions her body while shooting. The three most widely used handgun stances are Weaver, Isosceles and Chapman stance.

Twist

The length, within a rifled barrel, required to accomplish one full rotation. 1:12 Twist, means a bullet passing down the bore would complete one revolution in twelve inches. 1:7 Twist, means a bullet passing down the bore would complete one revolution in seven inches, which makes it a tighter twist than 1:12. Different weights of bullet require appropriate rates of twist.

Capper

A hand tool used in the field for inserting live and removing spent primers from cartridges.

LMG

Abbreviation for Light Machine Gun

Thumb Safety

An external, manual safety which is typically disengaged with the firing-hand thumb.

POI

Abbreviation for Point of Impact

Firing Line

A line, either imaginary or marked, from which people shoot their firearms down range.

Grip Panels

The interchangeable surfaces that are installed on the part of the gun that you hold. Users change grip panels to improve the look or feel of the firearm, or to personalize it so that the gun is more suited to a different hand size. Some grip panels are chosen for function, while others are chosen for looks. Common grip-panel materials are wood, plastic, and rubber.

Round Gun

Slang term for a revolver.

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.

Upset Forging

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

Percussion Cap

A small metal explosive-filled cup which is placed over the nipple of a percussion firearm. As the cap is struck by the hammer, it explodes and sends a flame through the flashhole in the nipple to the main powder charge.

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1