Bore / Caliber
Definition
Bore is the internal diameter of the barrel. Caliber is that diameter expressed in inches (.32,.38) or millimetres (9 mm, 7.62 mm). Shotgun gauge is the inverse measure (smaller gauge number means larger bore).
Related terms
- Ammunition
- The cartridge assembly fired by a firearm. Comprises case, primer, propellant and projectile. Defined under Section 2(1)(b) of the Arms Act 1959...
- Cartridge
- The complete round of ammunition: case plus primer plus propellant plus projectile, assembled as a single unit for breech loading.
- Firearm
- A barrelled weapon that launches a projectile by the rapid expansion of gas from a confined burning propellant. Includes handguns, rifles and...
- Primer
- The small explosive cup at the base of a cartridge that ignites the propellant. Conventional primers use lead styphnate, barium nitrate and...
- Projectile
- The object expelled from the barrel. Single bullet in rifled arms, multiple pellets or single slug in shotguns.
- Propellant
- The chemical charge that burns rapidly inside the case to generate the gas that drives the projectile down the barrel. Black powder...
- Rifling
- The helical groove pattern cut into a firearm barrel that imparts spin to the bullet, stabilising it in flight. Rifling lands and...
Explained in
- Firearms: Types, Classification, Ammunition and CompositionsBore is the internal diameter of the barrel. Caliber is that diameter expressed in inches (.32,.38) or millimetres (9 mm, 7.62 mm). Shotgun gauge is the invers...