In greyman gun speak, modern sporting rifles (MSR), typically AR type carbines as well as their cousins the SU-16, Ruger Mini-14, etc. are very effective for hunting, sporting uses and, increasingly, home defense. It is in the home defense role that these carbines come under fire for being 'too much gun.' It is a valid concern that .223/5.56 rounds can over penetrate both inside and outside at distances under 100-yards. However, the concept of a multipurpose longarm with huge magazine capacity, rapid use optics, and extended sight radius are very attractive in a home defense environment.
In a 2006 shootout with a Pennsylvania Police Tactical (SWAT) team and an armed assailant, this point is graphically driven home. The tac officers were armed with M4s in 5.56mm loaded with Hornady TAP 55 gr. and 75gr ammunition. The report states that, "Subject received approximately sixteen .223 rounds, thirteen of these rounds went completely through. One round struck his hip and completely shattered it. Another .223 round struck his aorta and another pierced and collapsed his lung. Both of these rounds lodged themselves inside the subject. The Medical Examiner stated that the .223 rounds caused massive internal damage." Amazingly, the subject still fought the officers as he was being handcuffed, even with 29 entry and exit wounds slowing him down before he finally expired.
- Supermushrooming PDX-1 ammunition, designed specifically for CQB use inside structure can help with over-penetration. (photo by Winchester)
While yes, this ended the threat, the fact that 13 of 17 rounds over-penetrated, points to the secondary danger of using high-powered assault rifle ammunition in an in-home situation. Some manufacturers have begun to look at this and design ammunition for use in close-quarters. These rounds still deliver incapacitating power while trying not to over penetrate.
An example of these is Winchester's PDX-1 Defender .223 round. This 77-grain Split Core Technology (SCT) round uses a soft allow tip bonded to a hard core to rapidly mushroom. It imparts 1068-ft/pounds of energy at the muzzle and according to tests will only penetrate 11-inches of gel. When compared to 9mm JHP ammunition, this is about three times the delivered energy on a bullet almost half the size. Other manufacturers like Black Hills with their 77gr match king offer similar performance. Frangible soft ammunition such as that for varmint use is another option. Rounds like these point to increased validity of .223 caliber carbines in home defense. Without these munitions, the .223 needs a healthy amount of thought given before using it inside a suburban home with sheet-rock walls. Using rounds such as 55-grain FMJ or surplus green-tip, you can often zip right through these structures and penetrate into the next room with enough remaining energy to cause damage.
Of course, in defense of the .223, many FMJ pistol caliber rounds will also over penetrate and are not stopped by drywall either. The fact that a .223/5.56 round will deliver a massive amount of energy when compared to a handgun round, and with better accuracy than shotgun rounds, it's a good choice for home defense.
Many carbine shooters find that, with enough time spent at the range, MSR's are easier to manipulate in high-stress situations than handguns. Most of the weapons manipulations needed t to operate the firearm is in the form of gross motor skills rather than fine motor skills. The longer sight radius provides as easier platform to line up your shot. Most of today's standard carbines come with Picatinny rails or other mounting systems for optics such as Eotech and Aimpoint sights that are very effective at point shooting. Many of these carbines can be very light (especially if you keep the accessories to what you feel you need rather than what you feel you want) and capable of one handed operation while you flip light switches and open doors.
While AR platforms in military service can often be heavy on the accessories, less can be more in the hallway of your home, especially if you have a cell phone in the other hand.
The same facet that made the MSR's selective-fire military cousins, the M16 etc. a favorite with ground pounders makes it a winner in high threat situations: carrying a large yet still compact magazine with a high capacity that can be replaced rapidly. If you have multiple assailants in your home, it is comforting to bring 30-rounds in one magazine to the party. This cannot realistically be duplicated by a handgun or shotgun.
-Legacy platforms such as this classic 1976 Ruger Mini-14, can have a very modern place in home defense if using the right ammo and tactics.
Using .223/5.56 carbines/MSRs for home defense is not everyone's choice, but it is a valid option that should be considered when looking at family protection.