ScopesGuide.com Glossary

Terms that start with O

An oil dent is a dent that forms in a cartridge case due to the applying of too much oil or lubricant.
Optics is the science of light and deals with the behavior and properties of light, especially with how light interacts with matter (solid objects).
Over penetrating is a term used when a bullet passes through its intended target and continues to travel striking something down range from the target.