Elevation - The vertical adjustment of a sight to bring the point of aim into coincide with the desired point of impact.


Energy - The amount of work capable of being done by a projectile at a given range, expressed in foot-pounds in the English system. Found by multiplying the square of the velocity in feet/sec by the weight of the bullet in grains and dividing by 450,400.


Engraving - The marks made on the bullet by the rifling.


Erosion - The wearing away of the bore of a firearm due to friction from the projectile, the action of hot powder gases, or the abrasive effects of partially burned powder grains.


Expander Ball or Button - The round steel part of a die that expands the sized neck of a cartridge case to the diameter needed to hold the new bullet firmly.


Expansion Ratio - Ratio of interior case volume to bore volume.


Extruded Primer - A primer that, on firing, has the metal of the primer cup forced back into the firing pin hole in the face of the bolt. Also known as cratering. Usually a gun problem, not a pressure sign.


Extruded Tubular Powder - Another term for cylindrical powder. Formed by forcing damp propellant mix through a die during manufacture and cutting to desired lengths. Usually has one or more longitudinal holes through the grains.


Extrusion - A shaping process that forces a solid mass through a hole of smaller diameter to produce a wire; used in the manufacture of bullet cores.