Any serious discussion of handgun calibers should begin with the acknowledgement that, when armed with a handgun only, you are distinctly disadvantaged in firepower, range and accuracy compared to most rifles and shotguns.  The only real reasons for choosing a handgun over a long-arm are concealability, convenience, and handiness.

     Concealability and convenience are obvious; handiness refers to their usefulness in close-quarters, like indoors or "social encounters", and the fact they can be used one-handed, while the off hand is otherwise occupied.

     Thus, you naturally want the most powerful, reliable, highest-capacity handgun possible (due to the firepower disadvantage) that will still fulfill the need for concealment, convenience and/or handiness.

     The three calibers that have been proven, through actual shooting incidents, to be the most effective in defensive shooting are the .45, .40, and .357 magnum.  Preferred loads are typically a quality hollowpoint, such as the Cor-bon, Gold-dot or Hydrashok JHP's.

     The following data is drawn from Evan Marshall and Dr. Fuller's studies on both ballistic tests and actual shooting incidents.

"Load" is the specific load, "vel" is velocity in fps, "Energy" is in foot-lbs, "Penetr" is avg penetration inches in ballistic gelatin, "F.Dia." is final diameter of recovered bullets, "One-stop" is the percentage of times, in actual shootings, that a single hit to the torso stopped a subject's attempt to attack or flee.  Hyd-Shok is Hydroshok, Goldsabr is gold-saber, JHP is jacketed hollow-point,

.45 auto
Load                                             vel.   energy   penetr   F.Dia. One-stop
230gr Hyd-shok                        850     349         12         0.78      94%
230gr Goldsabr                          875     391         14         0.75      93%
Corbon 185grJHP                    1150     544         11.3      0.70      92%

.40 auto
Corbon135gJHP                       1300    507           9.8       0.56     96%
Fedrl 155grJHP                        1140    448          12         0.65     94%
165gr Goldsabr                         1150    485          12         0.68     94%

.357magnum
Fedrl 125grJHP                        1450    584          12         0.65     96%
Fedrl 110grJHP                        1295    410          10         0.40     90%
125gr GoldSabr                         1220    413          13         0.60     84%

     Obviously, the .40 has consistently high stopping power.  The .45 is roughly equivalent.  The .357magnum, mostly a revolver caliber, has exceptionally good stopping power with an inexpensive Federal 125 grain jacketed hollow point.

     Secondary defense calibers, with lesser but still effective stopping power, are the 9mm and the .38 Special.  In both calibers, the most effective load is the Cor-bon 115 grain JHP+P.  Both of these calibers, especially the .38sp, are known to have limited ability to penetrate intervening obstacles like automobile windshields, or hard targets like the human skull.

Load                                             vel.  energy  pentr.   F.Dia. One-stop
9mm auto
Corbon115grJHP+P                1350     466      14          0.55     91%
Rem.124grGoldSabr+P          1180      384      12          0.65     83%
Win 115grSiltip                        1225      383        8          0.72     83%

.38special
Corbon115gr JHP+P               1250      399      15          0.58    83%
Win158grSWCHP+P                 890      278      15          0.62    78%
Fedrl 125grJHP+P                    945      248      12          0.69    73%

     Corbon 115grain Jacketed Hollowpoints +P(highpower) are the clear winner...but these hot loads are expensive and should only be used in high-quality guns that specifically say they are suitable for +P ammo.

     The calibers here termed as "Last Resort" are for times when it is impossible to carry anything but a very small handgun.  These are the .380 and .32 auto calibers.  The best .380 load is the Cor-bon 90 grain JHP+P, or arguably the 90 grain Hydrashok.  The best .32 load is either the 60grain Silvertip or Gold-dot...the Gold Dot may have better penetration.

Load                                             vel.   energy  penetr  F.Dia.  One-stop
.380 auto
90grCorbonJHP+P                  1050    220         9         0.58       70%
Fedr90grHydshok                   1000    200      10.5      0.58       69%
Fedr90grJHP                           1000    200       14         0.36       69%

.32auto
Win60grSilvertp                         970    125       6.5        0.57       63%
71grFMJ                                      905    129      18.5       0.32       50%

     The Gold-dot CCI-Speer .32 auto ammo is too new for definate data, but test results indicate .54 expansion with 8.3" penetration, indicating results comparable to the Silvertip, with better penetration.

     .22 and .25 caliber pocket pistols are nearly useless for self defense.  In particular, the .25 auto has the worst ballistics and stopping power of any handgun caliber.  While a .22long or .22magnum may inflict an eventually-fatal wound, they have little ability to incapacitate or STOP an attacker, making them unsuitable to defense.

     The famed .44 magnum, preferably in a Ruger Redhawk or Blackhawk, is an excellent field or big-game handgun-hunting round.  It is not really suitable for defense.  Recoil and muzzle blast are a problem for many shooters, and reduce the quickness and accuracy of follow-up shots; the .44 mag also tends to overpenetrate, and its added power does not significantly increase practical stopping power, as the following table shows:

Load                                              vel.   energy penetr F.dia  One-stop
.44mag
Win210grSilvertip                    1250     729        15      0.66       90%
Corbon180gUrban                    1200     576        15     0.70       90%

.44spec
Win200grSilvertip                      810     292        10     0.61       75%
CCI200grGold dot                       875     340       14      0.64      84%

     Exotic heavy-handgun calibers like the .454 Casul and .50AE, have far too much recoil and muzzle blast for all but the most dedicated shooters to master, and the increase in practical stopping power is small.   Therefore, such loads are not considered here.

     A statistical comparison of the various calibers and extrapolating from actual-shooting one-shot stop percentages, shows the THEORETICAL number of torso-hits required to achieve 99.9%+ stopping power.  Note that this is for comparison purposes, NOT as a guide to "how many times to shoot".   It does, however, reveal something about the relative effectiveness of various calibers.

Caliber and Load                   One-shot-stop  THEORETICAL #hits*
.45 230grHydshok                       94%                        3
.44mag 210grSilvtp                     90%                        3
.40 Corbon135grJHP                   96%                        2
.357mag 125grJHP                       96%                        2
9mm Corbon115grJHP+P           91%                        3
.38sp Corbn115grJHP+P             83%                        4
.380 Corbon90grJHP+P              70%                        6
.32 Silvertip                                   63%                        6

    The various information in this article reveals much about hangun ballistics and stopping power; however, no theory is absolute and for every rule there are exceptions.  In some cases, police have shot an individual repeatedly with 9mm and even .40 handguns, and had that individual continue to return fire...a point to keep in mind.

Goshin