Think of a lead ball which is the diameter of the inside of the barrel of the shotgun. The gauge of the shotgun is the number of balls that size to make up one pound. 12 balls - 12 gauge 20 balls - 20 gauge 28 balls - 28 gauge Exception - .410 bore is the actual bore diameter
bore diameter
A shotguns gauge is a measure related to the diameter of the smooth shotgun bore and the size of the shotshell designed for that bore. Gauge or diameter of the bore is determined by the diameter of 1 lead pellet times the number of pellets required to equal 1 pound. ex. 12 gauge is equal to the diameter of 1 of the 12 lead balls that equals 1 pound. ex. 20 gauge is equal to the diameter of 1 of 20 lead balls that equals 1 pound. ex. 3 gauge is equal to the diameter of 1 of the 3 lead balls that equals one pound. The larger number of gauge the smaller the bore.
.020
Valve guide bore can be measured using a bore gauge. The bore gauge is inserted into the valve guide, and the measurement is taken by expanding the gauge until it makes contact with the inner walls of the guide. The bore diameter can then be read directly from the gauge.
The bore is the inside of the barrel of the gun. Bore dimension for most rifles is caliber, which is the bore diameter in fractions of an inch or in millimeters. Some older big game rifles had designations such as "12 bore", which is bore diameter the size of a shotgun barrel of the same gauge. Gauge is the number of round balls fitting the bore that can be made from a pound of lead.
Most common sizes are .410 bore, 28 gauge, 20 gauge, 16 gauge, 12 gauge and 10 gauge. Note that .410 is the actual bore diameter forward of the chamber. See below for the meaning of gauge. There have been a much wider variety of bore sizes, especially back when muzzle-loading shotguns were common, since a shotgun that does not fire fixed ammunition can essentially have a bore of any size. There have been 8 gauge guns and even larger, mostly used by commercial hunters for killing sitting birds in large numbers. "Gauge," by the way, was originally determined by how many pure lead balls of bore diameter it took to make a pound.
This is a shotgun with an internal barrel diameter (called the "bore) of approximately .410" which shoots a shell which is about .410" in diameter. It is the only shotgun shell size that uses this convention. A 12 gauge shotgun, for example, does not have a bore of "12". A 20 gauge shotgun has a smaller bore than a 12 gauge and a 10 gauge has a bigger bore than a 12. Gauge size is based on the number of lead balls of the bore diameter which are required to make a pound (16 ounces). 10 balls, 12 balls, or 20 balls.
breadth, width, thickness; caliber, bore, gauge.
That's a pretty tall order. Do you have a specific question? The bore diameter of a 28 gauge is .550 inches. A 2 3/4 inch 28 gauge is equivalent to a 3 inch 410. It is not really a popular hunting gun, but is used by many skeet shooters.
Shotguns do not have a caliber. However, a 28 bore is 14mm or .55 of an inch.
Yes, it is larger, the smaller the gauge the larger the bore i.e. 3 gauge is larger in diameter than a 8 gauge or a 12 gauge.