Caliber
In guns, particularly firearms, but not artillery, where a different definition may apply, caliber (or calibre; sometimes abbreviated as "cal") is the specified nominal internal diameter of the gun barrel bore – regardless of how or where the bore is measured and whether the finished bore matches that specification. It is measured in inches or in millimeters.[1] Since metric and US customary units do not convert evenly at this scale, metric conversions of caliber measured in decimal inches are typically approximations of the precise specifications in non-metric units, and vice versa.
In a rifled barrel, the distance is measured between opposing lands or between opposing grooves; groove measurements are common in cartridge designations originating in the United States, while land measurements are more common elsewhere in the world. Measurements "across the grooves" are used for maximum precision because rifling and the specific caliber so measured is the result of final machining process which cuts grooves into the rough bore, leaving the "lands" behind.
Good performance requires a concentric, straight bore that accurately centers the projectile within the barrel, in preference to a "tight" fit which can be achieved even with off-center, crooked bores that cause excessive friction, fouling and an out-of-balance, wobbling projectile in flight.
Calibers fall into four general categories by size:
miniature-bore historically refers to calibers with a diameter of 0.22 inches (5.6 mm) or smaller
small-bore refers to calibers with a diameter of 0.32 inches (8.1 mm) or smaller
medium-bore refers to calibers with a diameter of 0.33 inches (8.4 mm) to 0.39 inches (9.9 mm)
large-bore refers to calibers with a diameter of 0.40 inches (10 mm) or larger
There is much variance in the use of the term "small-bore", which over the years has changed considerably, with anything under 0.577 inches (14.7 mm) considered "small-bore" prior to the mid-19th century.
Dance More
- 2024-08-09T00:00:00.000000Z
Sparks Meet
- 2024-07-26T00:00:00.000000Z
Get You Paid
- 2023-11-03T00:00:00.000000Z
Blow Up EP
- 2023-05-12T00:00:00.000000Z
What You Need?
- 2020-09-30T00:00:00.000000Z
Similar Artists