wadcutter: A special-purpose bullet specially designed for shooting paper targets, usually at close range and at subsonic velocities typically under 800 ft/s (240 m/s). They are often used in handgun and airgun competitions. A wadcutter has a flat or nearly flat front that cuts a very clean hole through the paper target, making it easier to score and ideally reducing errors in scoring the target to the favor of the shooter.
WCF: An acronym for a family of cartridges designed by Winchester Repeating Arms Company, called Winchester Center Fire, as in the .30-30 WCF or .32 WCF
wheellock: an obsolete mechanism for firing a firearm.
wildcat cartridge or wildcat: A custom cartridge for which ammunition and firearms that are not mass-produced. These cartridges are often created to optimize a certain performance characteristic (such as the power, size or efficiency) of an existing commercial cartridge.
windage: The side-to-side adjustment of a sight, used to change the horizontal component of the aiming point.