Probably the most popular firearm type in the world and have been around for over a hundred years. These handguns are very common and are made by hundreds of different manufacturers. These are magazine fed pistol and gets their name due to the "automatic" nature of the handgun to eject the spent cartridge, then recock the hammer and load a new round into the empty chamber each time you pull the trigger.

Some of the main reasons for the popularity typically are due to the increased ammo capacity. Most semi-autos hold anywhere from 7 to 8 rounds all the way up to 14 or 15 rounds in the magazine, combine that with the ability to swap out an empty magazine with a full one in just a few seconds, it's simple to see where the popularity comes from. The advantages do not just sit with capacity either, generally a semi-automatic pistol is "softer" to shoot as the expelled energy and force from the fired round is partially absorbed by the mass of the slide and the recoil spring, reducing shock assisting you to stay on target for follow-up shots.

For these reason it can be a great choice, but there are some things you should keep in mind. Although semi-automatics can be very reliable, they do require the ammunition to cycle properly and consistently. If it doesn't, this can cause malfunctions that will need to be address before the pistol will fire. This could become an issue in a self-defense situation.

There also is a matter of size, though semi-automatics are made in many different compact and sub-compact sizes they do still tend to have some bulk to them. This may no matter if you are just looking for a home defense weapon but can be a concern for a carry weapon.