Keep a 25 in your pockets as long as you like to have it, but never load it. If you load it you may shoot it. Shoot, and you can hit somebody, and, conversely, hit somebody, and, he hearkens, can be very angry with you. Col. Jeff Cooper. That quote continues to be repeated because it highlights an uneasy fact whenever it talks about defensive handguns: it is in the country of trade-offs. The cartridge must operate each time, it should go where it should go and it should be manoeuvreable enough to ensure that follow-up shots can be done quickly.
The difficult aspect about it is that the issues hardly appear in a spec sheet. They appear when ballistic gelatin penetration of 12-18 inches becomes the ruler, when ballistic gelatin holes are clogged by bulky attire, or when small guns prove to be inaccurate in their hits when their recoil should have been.
1. .22 LR in carry guns
The recoil of 22 LR is ideal on paper, and rimfire ignition is a reliability cost. Even with a .22 load that will deeply penetrate in gel, the platform-ammo with combo will not be as stress-resistant as centerfire choices. Combine the fact of small sights and short barrels on most carry-sized.22s, and the ease of shooting bonus might vanish at the moment of regular cycling and regular hits.
2. .22 ACP as a solid replacement of the .25 ACP
25 ACP was designed to provide the same performance as in the case of .22 on a centerfire platform, which it does. The contemporary snafu is that most of the.25 caliber pistol is of a geriatric design, has minimal sights, and the controls are small, which can cause the low recoil to become low hit at velocity. A 35-grain Speer Gold Dot shot on a gel test mentioned in a pocket-pistol walkthrough penetrated an average of 8.4 inches, a failure in the typical performance floor, though FMJ penetrated even more, at the cost of its own tradeoffs. The shooting data collected by Greg Ellifritz in reality is often summarized into a single ugly number that is 35 percent of the people who were shot in .25 ACP were not incapacitated.
3. .32 ACP when clothes and bullet construction fail to work together
The service history of 32 APC is long and it shoots softly, although soft shooting is not always accompanied with terminal reliability. Numerous loads are placed too near the edge that they are resolved by bullet construction and walls. In hollow points, expansion may fail to penetrate sufficiently when they break too soon, and may fail to extend at all when they become clogged. The comfort advantage of the caliber is real, however the performance envelope is so small that much of the heavy lifting is carried out by ammunition choice and realistic practice than many people are inclined to think.
4. .410 defensive loads out of revolvers
.410 handgun-length is a disguised versatility issue. The loss of speed occurs with short barrels, and dispersion develops rapidly enough to make misses and misplaced pellets plausible in a limited area. Patterns can be tightened with a longer-barreled.410 platform, called the Judge, certain loads, such as a four-pellet 000 buck option, which proved significantly more reliable in test, but mixed projectiles (particularly those with heavy payload) are erratic. Repeatable, accountable hits are the goals to be achieved, and even in this case, the strengths of the platform may lead in the wrong direction.
5. .380 ACP ammunition that will not penetrate in short barrels
380 ACP will work but it is at the edge of the penetration standard in most micro-pistols. In short barrels a few hollow points open rapidly and terminate soon; and others enter and swell irregularly, particularly on stratified apparel. The lesson of the engineering is easily learned: the variation in barrel length and bullet design has a greater impact in.380 than in larger service handguns. Shooters who prefer .380 obtain superior results as they are more concerned with consistency in gel-type measures and ensure reliability in a given pistol.
6. 10mm Auto, when the recoil and over-penetration becomes the actual problem
The reputation of 10mm is built on the speed and energy, yet the defensive performance is stipulated on penetration and growth. On a single structured gel project, 5 of 11 tested 10mm loads have passed both penetration and expansion threshold, and two others have over-penetrated slightly. The more practical problem is that so many factory 10mm hollow points are loaded with bullets that fit in.40 S&W, and when pushed at higher velocity can act erratically. At ranges where the shooter does not have the freedom to run fast, hit the target, the theoretical superiority of the caliber ceases to rent.
7. .38 Special, out of ultra-short barrels
Snub-nose .38s are carry-staples, although at less than two inches of barrel velocity is rapidly stripped away by physics. In revolver gel tests between two and four inch barrels, most loads of the.38 Special fell near the lower end of the optimum penetration curve and experienced numerous failures to expand when the bullet had to penetrate heavy clothing. The platform itself is mechanically reliable, but the ammo-and-barrels match might be intolerant: bullets which require speed to expand might not receive it, and +P pressure does not necessarily translate into improved actual performance in the shortest guns.
In these calibers, the repeating approach to failure is not weak, but rather inconsistent. When the cartridge is running on the edges, minor variations in barrel length, bullet design, clothing, and role of shooter result in wide variations. The very valuable engineering lesson is that the carry performance is a system: cartridge, load, gun size and the skills of the shooter to hit fast. Once any of the pieces has been constructed with a compromise in mind, the entire structure must also be fitted tighter to prevent the holes that keep appearing in gel blocks, and in actual world data sets.
