There are still a few serious 10-gauge fans around. Still, there are enough people shooting 10s for Browning to keep making Gold Light and BPS pumps in that caliber (Harrington & Richardson also makes a single-shot Pardner in 10-gauge).
The main reason people stop using 12-gauge is because it's so much easier to shoot accurately. A shotgun will only do what you make it do - nothing more and nothing less. If you want to be able to shoot accurately at long distances, then you need to use a gun that is designed for hunting large game at great distances.
Most shooters find that 20-gauge is the right size for most purposes. It's easy to handle and has enough punch to remove pests from a property. There are many quality brands of 20-gauge shotguns available today, so you should have no trouble finding one that meets your needs and your budget.
Used guns can be found online and in person across the country. Make sure to buy from a reputable source who can help you find a good deal on a used gun. Also, be sure to check the local laws before you purchase a used firearm. Some states require you to be 21 years old to purchase or own a handgun, while others may have different requirements.
By the 1890s, the 12 gauge had begun to supplant the 10 gauge as the all-around gauge, and by 1900, the 12 gauge had firmly established itself as the top gauge. By the 1920s, new progressive burning powders allowed for greater shot payloads, and all shotgun gauges improved in performance. The introduction of the semi-automatic shotgun in the 1930s further increased demand for larger gauges.
The rise of hunting with dogs brought about the need for larger shells to keep pace with their faster shooting counterparts. Shells over 12 grams were no longer rare, so 20-, 28-, and even 36-gauge shells became common. Today, only 12- and 20-gauge shells are used for hunting game birds like quail and pheasant. Animals like bears and deer are still generally hunted with shotguns containing between 16 and 20 gauge shells.
The most common shell sizes for hunting game birds are 6, 8, 10, and 12. Some species (like grouse) are limited to certain shell lengths. For example, only barrels that are not shorter than 48 inches can use 9- or 12-gauge shells. Other animals require different sizes of shells depending on what part of them is being harvested. Hens usually have two eggs per clutch, so they need large shells to protect both eggs. Males tend to fight more aggressively than females, so they need bigger guns too.
The 10 gauge is not solely for waterfowl and turkey hunters anymore. It is also used by deer hunters, especially when hunting in rough terrain where a more flexible gun is needed. The lack of power in the 10 gauge makes it ideal for these types of applications.
The 12-gauge shotgun was originally designed to provide more shot for less money. It succeeds in doing so but isn't used by wildlife officials anymore because it is too powerful for safe use against animals such as bears and tigers.
The 8-gauge is still used by wildlife officials because it is strong enough to kill large animals with one shot.
The 5-gauge is no longer manufactured because its small size makes it inefficient for killing large animals.
The 2-gauge is only used by children's shooting coaches because it has very small barrels that are easy to control. The lack of power in this gun makes it ideal for young shooters who are learning how to shoot safely.
The 1-gauge is only used by children's shooting coaches because it has very small barrels that are easy to control.