May 3, 2013

Thoughts...

First, you do realize Glasers come in .223 too, right? If you're that attached to the concept. They're redundant, but they sell 'em.

But your information is about twenty years out of date; the fact that .223 JHP penetrates less than pistol JHP and shotgun buckshot has been known since the early 1990s. For a primer (from 15 years ago, no less), I'd suggest Roberts G.K., "Law Enforcement General Purpose Shoulder Fired Weapons: the Wounding Effects of 5.56mm/.223 Carbines Compared with 12 ga. Shotguns and Pistol Caliber Weapons Using 10% Ordnance Gelatin as a Tissue Simulant", Police Marksman, Jul/Aug 1998, pp. 38-45. Or if you need something a little less academic, look at the pics here.

To quote the Roberts article, "When used with effective ammunition, the 5.56mm/.223 carbine simultaneously offers both greater effective range and less potential downrange hazard to bystanders than a 12 ga. shotgun, handgun, pistol caliber carbine, or SMG" (emphasis added).

*I'm* an AR-15 owner, and 55gr JHP (my own choice) penetrates less than the loads SWAT typically uses. LE/SWAT seems to be trending toward the heavier 62-77gr loads for more barrier penetration, since LE use goes beyond sheltering-in-place, but even that is less prone to overpenetration than handgun JHP. But for suburban civilian use other than in law enforcement, I think 55gr JHP/SP strikes a good balance; more effective than the fragile 40gr loads, but with less wall penetration than heavier-bullet loads.


AR-15's. Penetrate. Less. Than. Handguns.

Again---because it seems this is having trouble sinking in----a handgun has more chance of penetrating multiple walls and hitting an innocent than a .223 carbine using comparable ammunition, even though the absolute risk of both is quite low. Yes, if you shoot recklessly at an interior wall with *any* gun (even with Glasers), you can mortally wound someone on the other side of the first wall. But that is less likely with .223 loads than with almost any other caliber.

Re: Glasers, they were all the rage in late 1980's/early 1990's, but the consensus in the wound ballistics community seems to be that there are better choices now. I notice that even the Federal Air Marshals Service has now switched from Glasers to lightweight JHP for on-aircraft use. In 9mm, you're talking about a 75gr or 80gr capsule of very small birdshot at 1500 ft/sec, with neither the mass of a typical pistol round nor the velocity of a carbine. At $45 to $60 per magazine of Glasers, you can't exactly practice with them much, either.


Buckshot is buckshot; the lower recoil loads have a lower pellet count but roughly the same velocity and penetration, AFAIK. The shotgun still penetrates more walls than an AR unless you go down to birdshot, and birdshot isn't very effective at stopping a determined assailant beyond near-contact distance.


Huh? An AR shoots at exactly the same rate as a handgun; it fires once and only once when you pull the trigger, and will not fire another round until you release the trigger and pull it a second time. You don't seriously think Title 1 AR's "spray fire," do you?


In your hypothetical "regular home invasion scenario", I would be sheltering in place with 911 on speaker, not opening doors and moving down hallways. And in that scenario, an AR is just as handy as a shotgun, while offering more precision than a handgun or shotgun, more energy than a handgun, and less wall penetration than either. I have a 9mm if I need it, but if someone is trying to get in, I'll choose a long gun, thanks.

If your home layout is such that you'd need one hand to carry a child to the safe room, open doors to get to your child's room, hold a phone, etc. then sure, a handgun of decent capacity might be a better choice for you. But that's not my situation.

So you know where I'm coming from, I shoot USPSA matches with my HD guns (my AR and a S&W 9mm); stages are typically multiple targets from 2 to 20 yards, often with barriers or from cover, so yeah, I know how to run both at across-the-room distances. The handgun reloads faster, the carbine offers more precision.


It's not either/or. In your "jiffy," I have a handgun; in a couple more seconds, I have the carbine. With the carbine stored in a quick-access safe, it's at hand if I'm in the room.


An AR penetrates less than a handgun and is the same length as a shotgun. Pretending otherwise doesn't help your case.


Wrong, wrong, wrong. With lightly constructed, relatively long-for-width JHP like .223, velocity across different loads is inversely correlated with drywall penetration, while mass is directly correlated. A 40gr .223 at 3600 ft/sec might penetrate one interior wall; a 55gr JHP at 3000 ft/sec might penetrate two; a .45 ACP 230gr JHP at 830 ft/sec will penetrate three or four. Head over to the Box o'Truth and check out the sections on shotgun slugs and .45-70; *those* penetrate like nobody's business because of their mass.

The reason that fast .223 penetrates so little is that when you take a lightly constructed .22-caliber JHP spinning at 300,000 RPM and whack it with a couple slabs of drywall at Mach 3, it tends to destabilize, tumble, and fragment because the centrifugal forces exceed the tensile strength of the materials from which it is constructed. The same is not true of most handgun JHP, since handgun bullets are less long-for-caliber, are traveling far slower, and are less likely to fragment when transitioning from an axial spin to a tumble.


No. The momentum delivered to the target is equal to or less than the momentum delivered to the shooter's shoulder. If the 12-gauge doesn't knock the shooter on his/her ass, it won't knock a vest wearer down either. It could cause blunt trauma to someone not wearing a plate, or knock the wind out of them and drop them that way, but the main danger to the person wearing armor is from pellets that miss the armor.

That point is academic, though, since home invasions by people wearing armor aren't common.