(from Jul 2014)
Third in a series of tests of ammo from the AR-15. The AR-15 is becoming more common for home defense than ever before. In this video I explore military ball ammo, the 5.56x45 55-grain M193. The test barrel length was 16".
The M193 is a fragmenting round that relies on high velocity and yawing in the target to initiate fragmentation. The high velocity produces a massive temporary cavity, which gets magnified and turned into permanent damage by the fragmentation. When it works, it's phenomenal. Sometimes it doesn't work (such as when fired from too short of a barrel, which results in velocity too low for fragmentation to occur; other M193 failures can occur when the target is very thin, as the bullet may pass completely through the target before yawing).
I used genuine professional organic 10% calibrated ballistic gelatin to determine the penetration and expansion characteristics.
Note: I'm not making any claims for these videos other than that these are the results I achieved, in my own testing, from the stated pistol(s). I have no intention to make a blanket endorsement or indictment of any product, only to review and report what I found in a given instance. Obviously it is incumbent upon each individual to conduct their own research and make up their own mind about which defensive ammunition is best for their own purposes, in their own firearms. Also keep in mind that individual firearms can be persnickety; my AR15 may feed a particular round consistently whereas your AR15 might not work as well with those rounds, so -- please conduct your own testing before trusting any particular ammo.
The standards I use to judge bullet performance are the standards established at the 1987 and 1993 Wound Ballistics Conferences, and subsequently adopted by the FBI.