9mm ammo is great for small, compact, subcompact and pocket pistols.

• The round is physically small enough to facilitate a high magazine capacity in smaller magazines. Many 9mm subcompact pocket pistols hold as many as 10 rounds, give or take.
• The 9mm’s size and power also offers reasonably low recoil. A light subcompact pistol does not have the mass to absorb big recoil. A big round’s recoil is too hard for many to control in small, light pistols.
• The 9mm also offers better ballistic performance than other ammunition small enough for pocket pistols. It has seemingly dethroned the longtime pocket pistol champion, the .380, and for good reason. The 9mm provides a faster heavier round with more knockdown power than a .380 with only slightly more recoil.

Compact and subcompact firearm manufacturers and consumers are savvy to the practically tailor made 9×19 round. It is no surprise that it has become the standard for semi auto pocket pistols.

One thing to be wary of with any caliber fired out of any short barrel is low muzzle velocity, or the speed the bullet leaves the muzzle. Most pistol rounds are designed to be fired from a 4 plus inch barrel, which gives 4 plus inches for the gunpowder to explode and the expanding gases released from the explosion gases to expand, which push the bullet. Once the bullet leaves the barrel, whats left of the explosion and expanding gases has no effect on the bullet. When fired out of a shorter barrel, the bullet leaves the barrel earlier than the round is designed to accommodate. The gunpowder just burns too slowly and its full energy doesn’t transfer to the bullet before the bullet leaves the barrel., as the bullet has left the barrel before the gas has fully expanded. The bullet is only being affected by a fraction of it’s propulsion energy and will not reach its intended speed, delivering less energy or knockdown power down range. This can cause problems like cycling malfunctions, low impact power, under penetration and under expansion.

The good news is that specialty rounds intended for short barrels exists and claim to solve this problem. Faster burning gunpowder is used to ensure that the expanding gasses do so quick enough to sufficiently power the bullet before it leaves the short barrel. Since 9mm is so popular in short barreled pistols, ammunition manufacturers have given us no shortage of 9mm options for our compact and subcompact pocket pistols.