The 20 gauge is often thought of as the beginner's shotgun. Light recoil, readily available shells and plenty of shotguns with which to shoot them. When many people first shoot a shotgun, chances are it is a 20 gauge. It can take both game and targets with authority.
20 Gauge Basics:
- The nominal bore diameter of the 20 gauge is .615 inch.
- The 20 gauge is slightly smaller than the 16 gauge and larger than the 28 gauge. In the greater scheme of shotgun shells and gauges, the 20 gauge is considered the second most popular, sitting behind the 12 gauge.
- Today, the 20 gauge is used most in the discipline of skeet shooting, hunting notwithstanding.
- 20 gauge shells come in a variety of loads, both target and hunting. Slugs and buckshot loads are also available.
- The 20 gauge has been made in most every shotgun action that is available -- autoloader (semi-automatic), pump action, bolt action, break action (over and unders along with side by sides) and break action single shot. From a review of the relevant literature, the 20 gauge was never chambered in a lever action design.
A Bit of History about the 20 Gauge
The 10 and 12 gauge were well on their way for hunting purposes, the 16 gauge was floundering, the 28 gauge was considered a gun for women and children and the .410 bore was used for collecting specimens for biology. The 20 gauge fit a role the others didn't; it could do much of what a 12 gauge could do without the recoil. It could definitely outperform both the 28 gauge and .410 bore; it was better received than the 16 gauge simply because of recoil and, eventually, price considerations.
It is recoil that can wear out a shoulder and shooter in a hurry. The 20 gauge could be shot for practice in a shooting discipline and the shooter would still be fresh. And since it is better to learn the fundamentals of shooting a shotgun, sometimes thought more art than science, without fatigue, the 20 gauge fits the bill nicely.
Let us examine the 20 gauge in two different ways- by the actual cartridge itself and the firearms with which to shoot them.
Currently, 20 gauge shells range in size from 2 3/4 inches to 3 inches in length. This was not always so, with special sizes such as 2, 2 1/2 and 2 5/8 inches in length. The majority of shells produced today for the 20 gauge are 2 3/4 inches in length, with some 3 inch magnum shells produced for specific hunting purposes, such as ducks over decoys.
The maximum working pressures of this cartridge, according to the Sporting Arms and Ammunition Manufacturers' Institute is as follows:
- 2 3/4 inch — 12,000 PSI
- 3 inch — 12,000 PSI
So, whether a 20 gauge is either 2 3/4 or 3 inches in length, they both have the same maximum working pressures.
To give some reference in terms of other firearms chamber pressures (on average):
I mention these figures to give one an idea of how little PSI it takes in order to operate the 20 gauge.
Most reloading manuals give data that has an average working pressure of 9-10,000 PSI. The 20 gauge is similar to the 12 gauge in the sense that they are both quite forgiving for reloading accidents, such as using the wrong primer or charging the case with too much smokeless powder. Even so, it behooves the reloader to take as much care as possible in order to avoid blowing up your shotgun.
The majority of reloaders for the 20 gauge are target shooters; specifically, skeet shooters. The shotgun games of Skeet and Sporting Clays are not inexpensive to shoot; however, with reloading, one can bring the ammunition price down. Some people do reload the 20 gauge for hunting; but not many. With the recent importation of cheap shells, many people are no longer reloading, as they gain very little in the way of savings.
Reloading as it is, the vast majority of any manufacturers catalog for shotshells is made up of 12 gauge cartridges. <Winchester lists 73, Federal Cartridge Company lists 71 and Remington lists 70. For comparison, Winchester lists 22 20 gauge offerings.
Originally, shotguns were like every other firearm- it was a muzzle loader. Times progressed and we came to the point of firearms designed to shoot a self contained cartridge. Originally, there were only single shot and double barrel side by side shotguns. Times progressed further and we came to the first pump action shotguns and eventually to semi-automatics. It is conceivable to speculate that development can go no further in action types of any shotgun.
The most famous of the side by side double barrel shotguns are those made by the English firm of Holland and Holland and Purdey; in America, L. C. Smith and Fox. Winchester and Remington both have made single shot shotguns. 20 gauge over and under shotguns, where the barrels are stacked one upon the other, have been made by such reputable firms as the Italian Perrazi and the German Kreighoff. Semi-automatics and pump guns have been made by Winchester, Remington, Browning, Benelli and Beretta. The most famous semi automatic 20 gauge shotgun from the American makers would be the Remington Model 1100 with the Italian Beretta Model 391 surpassing it today. The two most famous pump action shotguns are the Winchester Model 1912 and Remington Model 870. Mossberg has probably produced as many cheap shotguns as anyone, so they should be mentioned as well.
20 Gauge Uses
As has been mentioned, the 20 gauge is used in a wide variety of hunting- from quail to chukar, to close range ducks over decoys. In terms of target shooting, the 20 gauge dominates the skeet shooting tournaments, giving the 12 gauge a run for its money, often beating the larger gauge. The 20 gauge is shot as a separate event in sporting clays. It holds its own (though not quite in parity) compared against the scores shot with a 12 gauge.
While not the 12 gauge, the 20 gauge does make an excellent target cartridge and gun. In small game/bird hunting circles, most people speak fondly of the 20 gauge. It is not as popular as the 12 gauge, but it settles quite well for being the little brother.
http://www.alliantpowder.com (for PSI data)