The 55 grain HP .223 has less penetration than any of the other ammunition tested. Based on the results of this testing, there appears to be no basis for concern regarding the over penetration of the .223 [HP] round. In fact, it seems even safer in this regard than .40 S&W handgun ammunition.
The hollow point cavity in the .40S&W round filled with material when shot through the wall. This caused [these bullets] to fail to expand when they entered the gelatin. As a result, they penetrated 8.5" farther than when shot directly into the gelatin.
When the .223 [HP] was shot through he wall it began to fragment and as a result penetrated the gelatin only 5.5".
Because the .223 [HP] begins to break up on impact, it has less potential for damage or injury than the 12 ga. in the event of a ricochet. The .223 [HP] is obviously safer in an urban environment than the 12 ga. with slugs or buckshot.
Y'all be safe now, ya hear!
Without God we have no moral compass. Without Family we have no purpose. Without Guns we can not defend either our religious choice, or our family! Millwright