In colloquial usage, the word "pistol" is often used as a generic term to describe any type of handgun, inclusive of revolvers (which have a single barrel and a separate cylinder housing multiple chambers) and the pocket-sized derringers (which are often multi-barrelled).

This means that, if you're carrying for protection, you have something very easy to shoot but also effective at stopping a threat. As handguns go, 9mms are also generally more reliable than smaller calibers because of the increased case capacity (and therefore recoil energy) over something like . 22LR, .