Definition: A shotgun's gauge is determined by how many round lead balls of that diameter it would take to make a pound. That's why the smaller the bore, the higher the gauge number is - because smaller bores mean more round lead balls will be required to make up a pound.
Most often, gauges are given in even numbers. Apparently that is just a matter of convenience. When gunsmiths were coming up with these standards long ago, they must have preferred dividing by an even number rather than an odd one.
To reiterate, a 10 gauge round ball weighs 1/10 lb, while a 28 gauge round ball weighs 1/28 lb.
The most common shotgun gauge is 12, but 10, 16, 20, and 28 are also used in modern shotguns.
The 410 bore is the exception to the rule, and shouldn't be called a "gauge." The 410 refers instead to a caliber, that is, .410 inch.
Pronunciation: gaje
Also Known As: Bore
Common Misspellings: guage, gage
Examples:
The 12 gauge shotgun is by far the most common found in the USA, and the smaller 20 gauge comes in second.
