There is no standard caliber of handgun that offers an assured “off switch.” The fact that the 9mm vs. .45 ACP debate is never resolved is due to the fact that both have the same ability to arrive in the same “good enough” terminal performance zone but act and feel differently when limitations are accumulated recoil, capacity capacity, obstacles, and the particular pistol firing.
Even the current defensive loads in both cartridges are routinely aimed at the same penetration bracket. The yardstick used in familiar is 12-18 inches of ballistic gelatin and the overlap is more than what most caliber tribes will acknowledge. It does not imply that all the loads are the same, or that the design of bullets is irrelevant. It implies that the choice and verification are even more important than the headstamp on the case.
The unquestionably starting advantage of the .45 ACP is diameter. A.45 is started at approximately .452 inches and a.9mm starts at approximately .355 inches and these shapes are likely to reappear after growth. Nevertheless, the expansion is not a caliber assurance, it depends on the impact velocity, cavity design, and barrel length. The lesson to be learned here is that “big” can be practical on paper, and still useless when a certain hollow point does not open at the velocity a certain carry gun generates.
The piece of that size, which is a barrel length, is where engineering comes in handy, and where forum talk becomes thin. The 0.45 ACP is frequently defined as a low pressure cartridge allegedly containing a quick burning powder, and is generally said to be less sensitive to barrel length than other handgun cartridges. Nonetheless, velocity can be shaved by shorter tubes, and velocity expanded by velocity gates. In published testing, a single sample load is given of 770 fps average velocity in a short barrel, and the general aim of the point is to ensure that the construction of the bullet must be sufficient to correspond to the speed which a small pistol actually can achieve.
Recoil is in which the spreadsheet becomes split times. Structured drills have produced data indicating measurably time penalties between 9mm and.45 when the same platforms are involved, but it is not a natural law of nature. The 9mm run at close range was 0.97 seconds compared to 1.01 seconds with .45 in a five shot string and the overall grouping was tighter with .45. It is not that one wins all the time, but it is the fact that the recoil alters the speed of the sight reaction and the frequency of high standards passing the timer.
The choice of platform will remove or amplify caliber differences. A heavy steel pistol might cause a feel of slower and smoother impulse of an .45, and a lightweight polymer weapon might create a feel of abruptness of the same cartridge. The choice of spring rate, slide weight, bore axis, and grip shape determine what the shooter feels is “manageable” and those mechanical decisions could be as important as the cartridge itself.
Capacity remains obstinately physical. In pistols of similar size, 9mm magazines usually have more rounds than the.45 since they are smaller. One comparison made is 17 rounds versus 13 rounds with similar full size designs. Extra attempts are not replacing skill, however they do modify the math when the shots are not perfect, the movement involved, or a reload needs to be disruptive.
The interior walls are not the answer to the missed shot issue and the choice of caliber does not turn the drywall to a “safe” side. In controlled materials testing, handgun rounds, 9mm and.45, were reported to penetrate several simulated walls with the findings summarized with at least six walls of sheetrock at common handgun loads. The practical point is that load choice is useful at the margins which backstop awareness and hit probability are the real load.
A place in which the .45 ACP retains a mere mechanical edge is suppressed use. Common weights of bullets used in the .45 are often subsonic, which does not produce the ballistic crack that will be observable when the projectiles travel above about 1,125 feet per second. Most 9mm systems require intentional subsonic load choice to achieve the identical effect, and most tilting barrel pistol systems remain in need of the appropriate booster gear to run with a can in place.
The unromantically throbbing limitation that trudges the others is training volume. More repetitions sharpen the draw, recoil management and decision making and that skill is cross caliber far better than the caliber myths cross internet. Where either cartridge is capable of achieving the present penetration and expansion goals, the variable of greatest importance is which pistol and load system can be operated with accuracy, repeatability and speed when the environment ceases cooperating.
