A home-defense handgun round must perform two tasks simultaneously: find the vital organs when the angles, clothing and movement become messy, and not cause additional harm in crowded areas. It is that commensuration which makes caliber debates immortal because the failures, the obstructions, the tension, all appear simultaneously.
The test of modern times has rendered one thing difficult to water, and that is this, that unless a load is capable of reliably penetrating to the 1218 inch window in calibrated ballistic gelatin it may be leaving too much to chance. And on the other end, when the cartridges strike like a freight train, then they may be controllably issues, and they may also continue to move when no one wants them to.
These calibers are continually found coming out the wrong side of that trade-off, either because they are incapable of doing the same job with consistent results, or because they bring with them sanctions that most households cannot readily learn to avoid.
1. .22 Long Rifle
The reason why 22 LR enjoys a good reputation as a training round is the fact it is simple to shoot. The issue is that very easy must also mean very reliable when it comes to home defense and the rimfire ignition is not as reliable as the centerfire in its mechanisms. That would have to translate into a greater probability of a click in the presence of a bang as the only solution to the problem.
The other wall that it runs into is the terminal performance. The use of numerous loads that generate minor energy means that on a large number of occasions, .22 LR is incapable of consistency in delivering penetration and disruption with the use of real-life impediments such as heavy clothes. What you have is a caliber which may be fatal, but too often, is subject to absolute conditions and absolute position.
2. .25 ACP
It was made to fit the small early pocket pistols, 25 ACP. Although a centerfire round, it usually has a very low energy, less than 70 ft-lbs typically, and that constrains what can be done with the bullet design to the target.
Moreover, the guns usually loaded with.25 ACP are usually older or astonishingly compact with few or difficult-to-manage sights. Those compromises come in a defensive moment, marginal ballistic performance along with platforms that are difficult to run fast and precise.
3. .32 ACP
32 ACP is in an exasperating purgatory. It is easy to carry and can be soft-shooting, although the caliber is often tied to small pistols which are already going to slow the speed. That renders expansion and penetration less foreseeable, especially when fabric comes into play.
It is a point of ballistic-gel procedures that the bullets must continue functioning upon hitting some barriers such as heavy clothes and the heavy-clothing test is not in vain: hollow points may be clogged and act as ball ammunition. The process of loading Lucky Gunner in which the loads are run through a four-layer clothing barrier explain why the consistency is more important than the best-case single shot in bare gel.
4. .410 Shotshell From Revolvers
.410 caliber revolvers in handgun sizes claim to be the solution of a shotgun in a handgun size. Inside, physics is not on your side. The reduction in velocity due to short barrels and the inability of birdshot loads to penetrate deeply enough to reliably strike critical anatomy are both issues.
Buckshot and slugs do make matters better, yet the platform continues to wrestle with the user: recoil, muzzle blast, and poor ballistic performance in comparison with specific purpose defensive handgun cartridges. The spreading sounding comfort also spreads payload and of course lessens the possibility that mass gets to where it is supposed to, in large enough amounts.
5. .380 ACP With Underperforming Loads
A 380 ACP will work though this is one of the calibers where ammunition selection may spell the difference between success and failure, particularly with the short barrels used in pocket-size pistols. Other loads swell violently and do not reach the depth of penetration in which the standardized testing establishes the length of reaching vital organs.
Gel testing systems that are constructed on the basis of FBI window-12-18 inches are not a guarantee of immediate stops, yet they do filter out loads that recurrently surface shallow. The small caliber size (easy to carry) is a benefit when loading.380 but a liability once the target is reached.
6. 10mm Auto (Normal Full-Power Loads)
10mm Auto provides serious energy, usually 600+ ft-lbs, and this power may be useful in certain applications. The priorities shift within a house. Many shooters are slowed by the recoil and blast of the cartridge and the performance of the defense is directly related to the capability of delivering repeat hits.
The other concern is travel. Bullet stops made of interior building materials are not dependable. Experiments of common construction materials underline the idea that that normal rounds can go through several layers of drywall; as the wall testing of USCCA points out, the interior walls are not going to stop a bullet. Small errors are able to travel further with a high-energy cartridge.
7. .38 Special out of Ultra-Short Barrels
There is a long history behind 38 Special, yet the snub-nose tax is not imaginary. Below about 2 inches in barrel length, velocity decreases with it and hollow points might not open as anticipated. +P loads will also recover some of the lost performance, but also increase recoil dramatically in lightweight revolvers.
The heavy-clothing gel methodology of Lucky Gunner points to the greater problem: a single shot has to appear good; a load must act predictably in a series of shots. That is more difficult with ultra-short barrels, which widen the dispersion between great and not enough performance.
8. .44 Magnum
44 Magnum invites movie-star vigor, which can be 1,000+ ft-lbs, yet home defense reprimands the wasteful. Fast, accurate follow-up shots are hard to achieve by most of them, and even the guns that handle the recoil of the muzzle blast are large and slow to maneuver in a tight area.
It is also an issue of penetration. With each time a cartridge is designed to plow through thick targets, it will have a high probability of moving further through the less dense structures. The fact that the walls are already known as being breachable by missed shots already means that indoor defensive planning is presupposing that the misses can then be loaded on top of that fact, making the outcomes of each error more severe.
The trend is similar in all eight: the incorrect caliber is hardly too weak or too strong to work in a vacuum: it is a noncongruence between the role the cartridge wants to play and the role demanded by the home defense when under stress.
Testing standards constructed of penetration in calibrated gel, along with real-world alerts that drywall is not cover, drive the choice of caliber to those which provide a compromise between control, reliability and predictability instead of extremes.
