“The caliber of the handgun is least important when it does not fit the boring criteria: it has to be able to ignite, the recoil must be felt, and it has to be able to penetrate the body enough to reach vital organs. The latter is what makes the long-standing FBI yardstick 12-18 inches of calibrated gel continue to appear in any serious discussion. It is not concerning knockdown power. Whether a bullet would still be pleased to do its work when clothing and angle and bone reduce the target to unheeding cooperation less than an unclothed range silhouette.
Others are attractive due to being soft shooting, small enough to fit into small pistols, or they have unusual payloads. The thing is that most of those perceived benefits are washed away by shallow penetration, irregular performance by short barrels or the unreliability of hits or misses in case the gun is dirty, the ammunition is old, and the shooter is in motion.
These are the calibers that most frequently compromise the part of achieving stopping, of a menace.
1. .22 Short
The 22 Short has a record of performance against it and history. It was constructed to perform low speeds and small activities, and that tradition can be traced to its area where it counts most depth. The cartridge light bullets and low-energy situation even under the best circumstances were a poor bet regarding consistent clothing and anatomy penetration. It still comes in handy where there is casual shooting and pests, but it cannot be used effectively on the defensive side where there is an excessive reliance on optimum positioning and favorable angles.
2. .25 ACP
The .25 ACP is allowed to be centerfire in small pistols, but the rear side is always a challenge. Pocket-gun testing in fabric into gel, loads of.25 ACP have been observed to plateau at about 10-11 inches -under the minimum of the FBI- at least -and exhibit little significant expansion as well. That performance difference is not academic; it eliminates any room of error whereby the shot lands to an arm first or to a sloping sideways.
The quote that is commonly quoted in training circles best describes its reputation; carry a .25 if it makes you feel better but never load it. Should you load it, you can shoot somebody, and they will get mad and do you a serious jury.
3. .32 S&W (Original)
The original.32 S&W is a time capsule cartridge: light recoil, low pressure, and intended to be used in a time when performance was not the key factor. Defensively, it has been merely superseded by its successor. Improved bullets and increased operating envelope, such as .32 H&R Magnum and.327 Federal Magnum, have been useful in modern.32-family rounds, and these are designed to shoot deeper and cut more reliably in realistic testing. The older .32 S&W does not provide that sort of consistency, particularly via barriers.
4. .410 Bore from a Handgun
A handgun of .410 makes the case simple; several bullets at the stroke of the trigger. Plated 000 buck can shoot up to 14.016.0 inches in unloaded gelatin in gel work on short-barreled .410 handguns, but the same weight has been found to fall to unacceptable ranges in the presence of heavy clothes. The lighter loads of birdshot fare worse; they cannot penetrate sufficiently to be depended upon to stop a determined attacker.
There is the problem with math, too. One published comparison gave each 000 buck pellet in handgun velocity approximately 72 ft-lbf of kinetic energy, and a 60-grain projectile of the .32 Auto was quoted at 125 ft-lbf. Spread is independent of penetration, and does not stabilize low per-projectile energy.
5. .22 LR (General-Purpose Loads)
Many people are able to shoot most of the time, and it counts, especially with 22 LR. However, the rimfire ignition and small bullets of the cartridge can transform it into an it depends caliber at the worst time possible. Short barrels usually remove velocity, and expansion is not dependable; where expansion occurs, it will usually be at the cost of penetration.
Defensive loads designed with that in mind try to take care of that by emphasizing depth. One of them was constructed to satisfy the 12 inch penetration standard, and factory gel results have been quoted at 13.75 inches. Yet even then, there is still the question of real world reliability issues; in one series of tests, the average sample failure rate was around one in 50-round boxes of one load, whereas in another series of tests, the sample was clean. It is the rimfire trade of controllability and capacity at the cost of less consistent ignition than centerfire.
6. .380 ACP FMJ
The border between ammunition selection where one may describe the outcomes of the action as works or questionable is 380 ACP. Full metal jacket rounds tend to feed well, however, they also make narrow wound tracks and may either under-penetrate (velocity and obstacles) or over-penetrate with minimal tissue destruction. The actual difficulty of the.380 is that it has a small operating window; the current manufacturers have brought the modern hollow points as near to the FBI minimum as possible, but not every load will actually arrive there with micro-compact barrels.
That is, it is not necessarily the problem of .380 ACP, but rather the problem of the wrong.380 load.
7. .45 GAP
.45 GAP is a method of addressing an engineering issue in packaging: .45-class performance in a shorter package to fit smaller grip frames. The point is not that it could not work, it is that it has never been able to gain a broad ecosystem.
Having less pistol and load versatility than the .45 ACP, the cartridge offers fewer choices in vetted defensive loads and fewer long-term avenues of parts, magazines and training acquaintance. At such defensive scale, hard to source will be a reliability problem, in its own right, just further down the line.
Caliber arguments tend to be concerned with what to be carried. The more practical filter is that which must be ruled out. The cartridges above are functional, some of them can be optimized to work more favorably with appropriate choice of load, yet all of them have one thing in common: a decreased tolerance to the appearance of barriers, angles, and imperfect hits.
In the event that the objective is regular halting execution, the tiresome benchmarks, penetration, dependability, controllability, remain unconquered.”
