GLOCK & AR15 pattern
Any serious self defense practitioners in the modern era own at least 1 copy of each. They are common in “free America”. Ammo for each is common 9mm and 5.56 respectively.
There are some that have a romantic interest in revolvers and shotguns. Both of which made more sense in the past than they do now. Revolvers and shotguns manual of arms are so dissimilar to each other that each requires a lot of training that does not transfer back and forth. This was not a problem in the past when more people hunted and were familiar with revolvers and shotguns. Many new shooters want to buy a shot gun in order to tick that box. They don’t realize that they need training and practice. They have no understanding of modern shotgun ammunition for self defense. Even if someone does everything right the availability of quality ammo is not good. the availability of a place to practice What they learned is worse. Go to a gun shop and look at the shotgun selection for self defense. You will find a large disparity concerning the manual of arms.
For self defense the pistol is not an option as much as it is mandatory. You can conceal it. you can carry it everywhere that is is legal to do so. even at home a long gun is impractical to carry slung all day every day.
If I start a client with a semi Auto pistol, almost everything I teach translates to the AR pattern rifle. They do need to learn the controls and the mechanical offset of the AR pattern rifle. I show my clients how to accomplish this with dry practice at home. Clients who do this can come to my class or almost any other and they don’t fumble the manual of arms.
GLOCK is Americas 9mm pistol. 9mm is Americas pistol cartridge. GLOCK all my gun friends own at least one. Most own a few. They come in a multitude of sizes, yet they all function the same. The triggers the safety the magazines all work the same. The GLOCK (as manufactured NOT Adulterated) is extremely reliable. Many other manufactures have made their own GLOCK clones. They usually attempt to “improve the trigger” which makes the trigger single action instead of double action. Pulling the trigger on a GLOCK does NOT just release the completely compressed firing pin and move the firing pin safety out of the way. It also finishes the job of fully compressing the firing pin spring. When a GLOCK is carried with a round in the chamber in a proper holster it cannot fire on its own. It does NOT have enough energy in the firing pin spring to ignite the primer. This makes it a safer gun than most other guns on today’s market for self-defense. The answer to the trigger is learn how to reliably use it as it came out of the box.