As instructors running a training company we get asked all the time "What is the best gun is for defensive and concealed carry?" In addition, we see students come through with all kinds of pistols in all kinds of shape, so we know what works and what does not for most people.
Size matter- Not necessarily the size of the bullet or caliber, but the size of the pistol. It has to fit you and your hand. If you cannot shoot it safely and accurately because it is too big or small for your hand, then it is not the right pistol for you. It does not matter what caliber it is if you cannot hit your target. Size/weight do matter- if the pistol is too big and heavy for you to lug around and carry comfortably -then you will not carry it and a firearm left at home is no good. I cannot emphasize enough how important size and fit is for you.
Sig, Smith & Wesson, and Sig (photos of 3 pistols), and Springfield Armory XD (single pistol photo- Credit Jon Boyd, from his article series "Which Pistol is Right for You"-links at the bottom of this article)
Sig- Any of their products classic or in the 320 series that you like and fit you are a good selection.
Smith & Wesson - Any of their pistols like the M&P2.0 in 9mm would be a good option if it fits your hand.
Glock- Any of the models that you like, and fit you- are a good selection. For example, a Glock 19 in 9mm is a perfect choice for me and the size of my hands.
Springfield Armory - XD or similar pistol are also good options.
We are leaving out revolvers and 1911s on purpose, as well as "small" pistols like the Ruger LCP and LC9. These are fine pistols for their purpose but for a beginner, they are to complex  or usually too small [LCP/LC9]. Now if you have very small hands or are a very small person, maybe the Rugers may work for you ( Editor Note: Keep in mind the smaller the firearm the more recoil is felt by the shooter).
These pistols are from quality makers, are well designed, rarely break and are the choices of professionals. Any quality gun shop can help you select a pistol that fits your hand and if you get one of the four listed above you will be well served. We always recommend shooting a few different pistols before you settle on the one that is right for you. If you wish to seek high-quality training that you can depend on and trust your life to, enroll in one of our courses. As a beginner to professional- train a little, a lot, and train often.
See our 4 part series on choosing the right pistol for you by Jon Boyd
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