what does gauge mean?

[45calibre]

As in 12 gauge and 20 gauge?

 

[Crystalship1]

As in 12 gauge and 20 gauge?

CLICKY ----> http://en.wikipedia.org/wiki/Gauge_(bore_diameter)

 

[Cwood]

gauge equals bore diameter

12 gauge is .729 inches

20 gauge is .615 inches


Shotgun - Wikipedia, the free encyclopedia

The caliber of shotguns is measured in terms of gauge (U.S.) or bore (U.K.). The gauge number is determined by the number of solid spheres of a diameter equal to the inside diameter of the barrel that could be made from a pound of lead. So a 10 gauge shotgun nominally should have an inside diameter equal to that of a sphere made from one-tenth of a pound of lead. By far the most common gauges are 12 (0.729 in, 18.5 mm diameter) and 20 (0.614 in, 15.6 mm), although .410 (= 36), 32, 28, 24, 16, and 10 (19.7 mm) gauge and 9 mm (.355 in.) and .22 (5.5mm) rimfire calibres have also been produced (although 10, 12, 16, 20, 28, .410, and .22 are the only legal hunting gauges/calibers in most U.S. states). To further complicate matters, typical handgun chamberings such as 9 mm Parabellum, .45 ACP, .38 Special/.357 Magnum, .44 Special/.44 Magnum, and .45 Colt and others bearing a "shot" load have been brought to market by CCI/Speer--either crimped in or in a plastic casing replacing the bullet. These are not generally considered "shot shells" by shotgun users, and the patterning performance is questionable since they are fired through rifled barrels. Thompson/Center makes special pistol barrels in .38/.357, .44 and .45 Colt that have "straight rifled" chokes in them to reduce the spin of the shot column and produce better patterns, but they are still suitable only for pest control at very short ranges. Larger gauges, too powerful to shoulder, have been built but were generally affixed to small boats and referred to as punt guns. These were used for commercial water fowl hunting, to kill large numbers of birds resting on the water. Although relatively rare, single and double derringers have also been produced that are capable of firing either .45 (Long) Colt or .410 shotgun shells from the same chamber; they are commonly known as 'snake guns', and are popular among some outdoorsmen in the South and Southwest regions of the United States. There are also some revolvers, such as the Taurus Judge, that are capable of shooting the .45LC/.410 rounds; but as with derringers, these are handguns that shoot .410 shotgun shells, and are not necessarily considered shotguns themselves.

 

[Joe Williams]

It is a measure of how many lead balls that are the diameter of the bore it would take to make a pound.

 

[tyrajam]

Its a wierd measurement, it actually refers to the number of lead balls that size that equal a pound, ie it takes 12 balls the diameter of a 12 guage barrel to weigh one pound

 

[Panama]

It actually makes sense to me.
"A 10 gauge requires bigger balls"

 

[dburkhead]

Its a wierd measurement, it actually refers to the number of lead balls that size that equal a pound, ie it takes 12 balls the diameter of a 12 guage barrel to weigh one pound

It's not so weird when you consider how small arms ammunition was manufactured in the early days.

Musket balls and other round lead projectiles were generally produced in a drop tower (thus, the term "drop shot"). Molten lead was poured into a vessel at the top in which holes had been drilled. As the lead fell, the natural cohesion of the molten lead caused it to split into "drops" which became spheres. Ideally, the molten lead balls would solidify by the time it hit a pool of water at the bottom which broke their fall and prevented them from being too badly deformed. (IIRC, that's not really necessary--lead is dense enough that even molten it will retain it's shape relatively well on hitting the water at those speeds.) This process actually does a pretty good job of producing quite regular spheres of very consistent size.

From that starting point, a simple way to measure the size is simply to weigh a bunch of the lead balls--10 to the pound, 12 to the pound, 16 to the pound, what have you.

And, once you have the shot, it's far easier to drill the gun bores to the size of the shot than to adjust the temperature of the lead, distance of fall, size of the holes in the vessel at the top of the tower, etc. to tweak the size of the balls, so you use the size of the ball (12 to the pound, for example) as the gauge of the bore.

Shotgun gauges are simply a holdover from that early production method. We see something similar in early artillery, both shore and naval, in guns classed as "six pounder" or "32 pounder carronade" or what have you. Although in artillery it was the size of iron spheres and I don't think iron was ever done as drop shot (could be wrong on that though).

And that's your history of armaments lesson for the day.

 

[JByer323]

Huh, I had no idea. Good question, good info.