This is used with permission from DocGKR (Dr. Gary Roberts). I'm reposting this here because I feel like it is amazing information resource and should be shared with everyone, so we can understand the truths and myths about ballistics of different firearms and be better armed if (God forbid) we ever have to defend ourselves against another human being.
I found this information very helpful and hope that you guys do too.
For the most up-to-date version of this information, please see his original thread here:
http://www.m4carbine.net/showthread.php?t=44869As many of the previous posts note, there are multiple factors that will play a role in determining which weapon might be the best choice for home defense.
From a pure wound trauma standpoint on a shot against unarmored soft tissue, a close range hit from a 12 ga shotgun using buckshot will create more damage than any 5.56 mm projectile; it is for this reason that Dr. Fackler has expressed his preference for 12 ga buckshot over 5.56 mm for close range defensive use. Compared to pistol caliber weapons, virtually any shoulder fired carbine caliber weapon or 12 ga shotgun will prove superior from a wound ballistic standpoint. Keep in mind that over the past 20 years, the vast majority of the 5.56mm/.223 loads we tested have exhibited significantly less penetration than 9mm, .40 S&W, .45 ACP, and 12 ga. shotgun projectiles after first penetrating through interior walls. Stray 5.56mm/.223 bullets seem to offer a reduced risk of injuring innocent bystanders and an inherent reduced risk of civil litigation in situations where bullets miss their intended target and enter or exit structures, thus 5.56mm/.223 caliber weapons may be safer to use in CQB situations, home defense scenarios, and in crowded urban environments than handgun service caliber or 12 ga. weapons. Below are the wound profiles of unobstructed shots at 3 meters, comparing several weapons that might be used for home defense:
Note that the M1 carbine, 16” barrel AR15, 18” barrel shotgun with a “youth” stock, and 16” barrel lever action carbine are all approximately the same length and offer the equivalent ease of maneuvering, so bickering about weapon size is a somewhat moot point when comparing weapons of this type. From an ergonomic and weapon manipulation standpoint, the AR15 is far superior to the other weapons, followed by the M1 carbine, and then distantly trailed by the shotgun and lever action carbine. Likewise, the AR15 is the most modular and allows the easiest mounting of various accessories. Unfortunately, AR15’s are also usually more expensive. In addition, in some locales, AR15’s are more highly regulated and/or feared than other less “scary” looking weapons; in those areas, an AR15’s “military” appearance may prejudice some LE officers who respond to a lethal force incident, as well as the DA and jury… If living in a state with asinine legal restrictions on firearms regulations or a liberal “weapon phobic” region, a PC, plain-jane appearing shoulder fired weapon that does not scare the metaphorical sheep might be prudent…
In an indoors static defensive role against a single violent assailant who was advancing on me, a 12 ga. shotgun would be my first choice. However, if there are multiple criminals assaulting me or in a time of domestic unrest and upheaval with potentially large crowds of hostile individuals roaming about, or in situations that would require movement outdoors, then I would far prefer a magazine fed shoulder fired weapon capable of greater range, faster reloading, and greater ammunition capacity than a shotgun.
Finally, there is the matter of weapon familiarity and training. In 20+ years of military and LE use, I have fired far more rounds of ammunition, had more training with, and greater experience using AR15 based rifles than any other type of shoulder fired weapon. And while I have also trained with and used other shoulder fired weapons including MP5’s, M14’s/M1A’s, shotguns, bolt guns, and the odd M1 Garand, M1 carbine, and lever gun—baring legal restrictions, in a chaotic, stress filled situation, I would feel most comfortable and confident using an AR15 based weapon due to my previous training and experience.
