9mm pistols come in all shapes and sizes, from full size service
pistols (Glock 17, Glock 19, Beretta 92) to the pocket sized Kahr and
Kel-Tec. Also, there are a few rifles chambered in 9mm, the Marlin
Camp Rifle and a variant of the AR-15 from Bushmaster. Additionally,
there are several machine pistols available in 9mm, including models
from Heckler and Koch, among others. Lookalikes to the machine
pistols include the Tec DC-9.
Generally, 9mm guns are semi-automatic, magazine fed pistols. To the
untrained eye, they all look about the same - black or silver, usually
with an external hammer, and no 'wheel' in the middle that signifies a
Also, the 9mm designation can be misleading; there are several pistol
cartridges made in 9mm. The most common is the 9mm Parabellum or 9mm
Luger, technically known as the 9x19. That stands for a 9mm slug with
a case length of 19mm. This is the NATO standard round. There is
also the 9x18 Makarov, only used in the Makarov line of pistols from
the former Soviet block. And, going smaller, there is the 9mm Kurtz,
which is the same as the .380 ACP round, with a 17mm case.
Stepping up in the sizes, you have the 9mm Largo, or 9x21 round, which
is an odd variant used only in some rare collectable guns. This isn't
something you'd find in the local gun shop. Others are the 9x23
Winchester and 9x23 Winchester Magnum, two specialty rounds.
Additionally, pistol rounds that use a 9mm slug include the new .357
Sig, which is a .40 case necked down to .355, or 9mm and loaded with a
heavy powder charge. This round looks like a minerature rifle round.
Addressing your question of power, most 9x19 pistol rounds produce
about the same power. We're going to treat power as foot pounds of
energy for conviniece sake. This is a measure combining both velocity
of the round and the weight of the projectile.
Given that all rounds are fired from a 4" barrel, the charts from
Winchester Ammunition show energy at the muzzle as follows:
Brand Foot Pound Enegry
147gn SXT 320
115gn Silvertip 383
115gn USA FMJ 362
For comparison, the 9mm Kurtz (.380 ACP) generally only has about 300
foot pounds of energy. The 9mm Makarov only packs a punch of 210 foot
pounds. However, the .357 Sig has 505 foot pounds of energy, and the
9x23 Winchester Magnum has 555 foot pounds of energy at the muzzle.
To answer your question about which gun that looks like a 9mm and has
the most power, well, that's a wide open field. Generally, the AMT
Desert Eagle in .50 AE is considered the most powerful semi-automatic
pistol. It fires a 300+ grain slug that is a full half-inch in
diameter at around 1300 feet per second, with a muzzle energy of over
1,260 foot pounds - more than 4 times the energy of a standard 9mm
round! Very fun to shoot, too; loud, powerful and accurate. They are
quite heavy, and very expensive, starting at over $1,000.
Some good information on the Desert Eagle has been written up by
Duncan Long at:
If you are wanting to stay in the same general size as a 9mm pistol,
you can choose from a .45, a .40, or 10mm S&W, or .357 Sig. All of
these are powerful, with perhaps the most powerful being the .357 Sig
I've found a few images of semi-automatic pistols in various calibers,
linked below. If you'd like further information, please ask for
clarification before rating this answer.
Images of Firearms:
Desert Eagle .50 AE
Kel-Tec P-11 9mm
Kel-Tec P-32 .32
Colt 1911 A1 in .45
Browning High Power 9mm
CALIBERS -- Choosing Defensive Ammunition by Todd Louis Green
General Info on Metallic Ammunition Cartridges
Online Conversion - Energy Conversion (select joule and foot pound)