@Officer Hotpants
These days in American cities there are gangs doing home invasions in broad daylight. You may find yourself with half a dozen unwanted armed guests, not one, and such events occasionally turn into extended firefights.
When I was much younger I was proud of my skill with a shotgun… but when I ponder having only four, five, or six shots to work with, and having to reload a tubular magazine one at a time while people try to kill me–I decided that perhaps a modern rifle with a detachable box magazine and good capacity might be preferable.
Anyway. 5.56mm M193 Ball is 1960s technology and very, very good at close quarters distances. This diagram is from a guy named Fackler, who has written extensively about wound ballistics and also surgery. He’s an Army surgeon.
This type of bullet has a strong tendency to yaw and tumble in soft tissue shortly after entrance, though the exact point where it will become unstable cannot be predicted, and can be much longer or much shorter than that, for reasons not fully understood. If its velocity is sufficient, when it yaws about ninety degrees it breaks into fragments. The fragments continue moving forward, making many small holes in tissue. The hydrostatic shock wave following just behind them stretches the tissue past its elastic limits, tearing it where the fragments have gone and destroying a considerable amount of tissue.
The 12 gauge can be very good for antipersonnel work at close range, or it can be mediocre. Speaking of birdshot:
The yellow stuff is ballistic gelatin, a solution 10% by weight in water and calibrated to verify that it behaves more or less like human soft tissue. That’s #8 birdshot. Note that it only goes in 5” to 6” and stops.
Buckshot is greatly superior for antipersonnel work:
For scale, the pellets entered at the right and traversed about a foot and a half of gelatin before coming to rest. Note the disruption near the entrance wound due to temporary cavitation of the material.
The FBI tells us that to be useful for antipersonnel work, a bullet must penetrate at least 12” of calibrated 10% ballistic gelatin, and preferably stop at or before the 18” mark. This is because the bad guy trying to kill you is probably not going to square up with his sternum exactly perpendicular to the path of the bullet. The bullet is likely go through an arm before entering the torso–the FBI says it happens about 40% of the time when their agents are involved in shootings in the field. Birdshot can work but it has to be very close and everything has to be exactly perfect in terms of where it hits. Buckshot gives you more margin for error.
And with modern rifles, with which we are not bound by the rules of the Hague Convention, we are allowed to use expanding bullets, and choices like this are available to us.
The bullet is designed to expand and begins to fragment into metal splinters upon impact with something solid. The splinters move forward through the gelatin–or soft tissue which it simulates. Hydrostatic shock pushes open a cavity after they pass. As the tissue in the vicinity of the path of the largest bullet fragment is stretched, it tears at the places where the fragments have riddled it, giving performance like this.
Of course, hypocrite that I am, my primary home defense gun is an AK in 7.62x39mm, loaded with cheap FMJ. If the ongoing ammo shortage ever lets up a bit, I will need to remedy that and replace them with softpoints.
@Anonymous #372F
In the US police departments used to use shotguns to disperse rioters. They still sometimes use the term “riot gun” to describe a shotgun. They would shoot birdshot at them and try to ricochet their shots off the pavement just in front of them so the pellets would lose some velocity and energy and hit them in the shins and knees. It still killed people occasionally, and American police departments stopped doing that about a hundred years back. Baton rounds also occasionally kill people. This is generally regarded as a bad look, from the public relations perspective.
But at the same time, a statistic I keep seeing, though I have never been able to find a source, says that all shootings with all shotguns in the US, one shot is lethal to the recipient 80% of the time. This includes all shootings, self-defense, criminal acts, and suicide, and all calibers of shotgun and types of ammunition. I find it plausible, if not perfectly convincing. It is usually quoted by people saying that centerfire rifles kill 40 to 50 percent of the time, and handguns under 5%.