Firearms with two barrels placed one above the other.
Archives: Glossary
Glossary custom post type
OVERALL LENGTH
1. Firearm: The dimension measured parallel to the axis of the bore from the muzzle to a line at right angles to the axis and tangent to the rearmost point of the butt-plate or grip.
2. Ammunition: The greatest dimension of a loaded cartridge, i.e., from face of the head to the tip of the bullet for centerfire or rimfire or to the crimp for shotshells or blanks (not to be confused with the uncrimped length in a shotshell.)
OVER-BORE
A shotgun barrel bore diameter greater than the SAAMI maximum for that gauge. Also called a Baker Bore.
OVER-BORE CAPACITY
The point where the powder charge of a particular burning rate of propellant exceeds the capacity of a barrel of specific caliber and length to convert the propellant gas pressure to velocity.
OVERPOWDER WAD
Various designs of separators, made of various materials and used between the propellant powder and the shot pellets.
OVERTRAVEL
The distance after a particular event occurs in the normal operation of the firearm, e.g. additional rearward motion of the trigger after sear or hammer release.
PALM REST
An adjustable support for a target rifle extending downward from the forearm.
PAPER DISC
Small circular piece of treated paper cut and pressed into the primer cup in contact with the priming mixture. Also called Foil.
PAPER SHELL
Shotshells which are constructed with a body made from paper tubing.
PARKERIZING
A non-reflecting, rust-resistant finish used on metal surfaces of some firearms. Also called Phosphatizing or Phosphate Coating.