When thinking about using an AR-15 for home defense, I’ve conducted a few tests of ammo made specifically for self-defense purposes; rounds like the Winchester PDX1 proved to be a phenomenal performer, and it did something that military ammo isn’t allowed to do — it incorporates an expanding hollowpoint into its design. The Hague Convention prevents the use of expanding bullets, so a design like PDX1 can’t be used by the military. So what can military ammo do?
A lot. In this test, I put M193 through a block of ballistic gel to see what kind of damage it can do. Military ammo can’t expand, but it can fragment, and fragmentation is one of the chief ways that military ammo wounds. Self defense ammo (like Winchester’s PDX1) can fragment too, and make good use of it as well, but fragmentation is all that the M193 is allowed. Even so, it’s enough to create a truly horrifying amount of damage — when it works.
M193 doesn’t always work properly; it relies on high velocity to fragment so it’s not necessarily a great choice for use in a short-barreled rifle where the velocity might be below the threshold for initiating fragmentation. In this test, I used a 16″ barrel and shot from a distance of about 10 feet. Most home defense situations should be well within 50 feet or less, and the 16″ barrel proved more than adequate to deliver enough velocity to ensure huge cavitation and fragmentation. Unfortunately the chronograph didn’t give a reading on this shot so I can’t tell you the exact impact velocity, but the results show that it was enough.
With all that said, and even after viewing the damage, I’d still lean towards choosing PDX1 or Controlled Chaos .223 loads over M193. All three rounds create tremendous damage, but the PDX1 adds an additional component to the mix — it has a hollowpoint bullet that penetrates over 13″ deep for an additional wounding factor that the M193 doesn’t have. Controlled Chaos has a non-expanding bullet that ensures deep penetration too. Given the scale of damage done by the M193, you probably are not going to need that additional wounding factor of the deep-penetrating hollow point bullet. But if it’s my life on the line, I’d want every advantage I could get. I’d load my home-defense AR15 with PDX1 first, but I’d have plenty of M193 on hand as well; it’s much cheaper than brand-name self-defense ammo, and it can be devastating.