This question will be debated until there is no more ammunition.
All of us have been exposed to the varying theories regarding which type of handgun bullet is best for defensive purposes. Some proponents (Dr. Julian Hatcher) believe that "bigger is better" while the National Institute of Justice performed a "computer man" study a number of years ago which suggested that light and fast bullets achieved the most lethal results.
As more and more data becomes available, theories change. Evan Marshall wrote definitive studies in 1992, 1996 and 2000 after examining the results of thousands of actual shootings. His conclusions came as a result of actual shootings and not from firing bullets into wet newspaper, gelatin or some other artificial medium.
His data is based on "one shot stops". This is defined as: 1. a single hit to anywhere on the body not counting the head, neck or extremity shot: 2. when a subject stops shooting or striking blows if that was what he was doing and 3. runs no more than 10 feet before collapsing. In other words, Marshall’s studies examine what happens in the first few seconds after a shooting.
In the past decade, major advances have been made in bullet design which adds to the lethality of the projectile. Every major US bullet manufacturer has their own proprietary projective which they claim is best for the job at hand. New calibers such as the 357 SIG have appeared on the scene while more data has been accumulated on relatively new bullets such as the 40 Smith & Wesson. Marshall’s newest study takes these events into consideration.
32 ACP - Most of the smaller caliber firearms such as this caliber and the .380 ACP are carried as "back-up" guns by law enforcement thus the increase in data from actual police shootings. The CorBon 62 gr. JHP round was involved in 17 shootings with 11 one shot stops which achieved a 65% rating followed closely by the Winchester 60 grain Silvertip which was fired 162 times and caused 104 stops for a 64% rating. The Federal 65 grain Hydra-Shok and the CCI 60 grain Gold Dot achieved one shot stops 63% and 60% of the time.
380 ACP - The top rounds in this category were the Federal 90 grain Hydra-Shok and the CorBon 90 grain JHP+P which both rated a 70% one shot stop rating. While Federal 90 grain FMJ ammo was used in a whopping 245 shootings, it only achieved 55% one shot stops.
38 Special - With the introduction of semi-auto pistols, this caliber was relegated to secondary status. This data is from 2 and 3 inch revolvers which limit muzzle velocity & therefore results are less than other comparable calibers. Both the Winchester and Federal 158 grain LHP+P offerings were involved in 158 shootings with the Winchester round making 121 single shot stops for a 68% rating and the Federal loading making 120 one shot stops for a 67% rating. Most all of the 16 loadings examined fell in the 60 percent range with the Federal 125 grain Nyclad LHP+P round earning a 61% rating. It’s clear than the long-used 158 grain lead hollowpoint pushed to +P pressures is the best round for this caliber.
357 Magnum - Once the king of law enforcement handguns, this caliber has also been replaced by large capacity auto-pistols. The data collected for this caliber came from 2 and 3 inch revolvers, not the longer barreled type. The top round was the Remington 124 grain JHP followed by the same loading by Federal. Both loads achieved a 91% one hit stop rating. Most other loads ranked in the 80% area with the Federal 158 grain Hydra-Shok achieving a 78% rating.
357 SIG - This is the most current law enforcement cartridge and therefore, shooting data is limited. The top rated cartridges were the Remington and Federal 125 grain JHPs. Both were rated at 91% one shot stops. Of the 9 loads evaluated, the poorest was the Federal 158 grain Hydra-Shok which was involved in 41 shootings with 32 one shot stops for a 78% rating.
9mm - This was the first semiauto pistol to be used extensively by police agencies and replaced the 38 Special and 357 Magnum round. Early loadings of the 147 grain round caused major stopping problems however current 147 grain designs are vastly superior. Clearly the best 9mm loads are those driven to +P+ pressures. Of the 20 loadings evaluated, the top load was the Federal 115 grain JHP +P+ involved in 209 shootings with 190 one shot stops for a 91% rating. The Winchester 115 grain JHP +P+ and 127 grain Ranger SXT +P+ both had 90% one shot stops. All five loads driven to +P+ pressures ranked in the top 5 followed by all bullets loaded to +P pressures. Rounds manufactured to standard pressure ratings comprised the bottom 12 loadings in the study.
40 S&W - This caliber has become extremely popular with law enforcement agencies due to the perceived deficiencies of the 9mm round. All manufacturers have at least 2 loadings of this caliber and it has served very well. The Remington 165 grain Golden Saber was used in 311 shootings and made 292 one shot stops for a 94% rating followed closely by the CCI 165 and 155 grain loadings and the Federal 155 grain Hydra-Shok bullet. These 3 loads made 93% one shot stops. Other manufacturers loads in the 90% range were the Federal 155 grain JHP and the CorBon 135 and 150 grain JHP bullets. Thirteen other loadings were evaluated with the poorest being the Winchester 180 grain FMJ that was involved in 134 encounters and made 95 (71%) one shot stops.
45 ACP - This caliber has been around for almost 100 years and is still the top rated round. More police agencies are using this round due to its proven stopping ability. The large diameter, heavy bullet is the basis for the "momentum" theory of stopping power however actual results in shootings show a mix of "light and fast" and "slow and heavy" rounds. The Remington 185 grain Golden Saber was involved in 148 shootings and caused 142 one shot stops for a 96% rating followed closely by the Federal 230 grain Hydra-Shok which caused 200 one shot stops in 211 shootings for a 95% rating. Eight of the 16 loadings examined rated above 90% one shot stops while 5 others rated in the 80s. The poorest stoppers were the Remington, Federal and Winchester 230 grain FMJ rounds which achieved 62% one shot stops.
It’s difficult to say that one type of bullet is best for all calibers and, in fact, these study results show that the best results come from a mix of heavy to light bullets which defy most theories. It is clear however that some loadings are much better than others and the decision is ours with respect to which we choose.