They use frangible bullets. Not designed to penetrate solid objects. Just don't steep in front of one.

Here's the thing on this whole assault weapon ban. The proposal does not fit the statistics. Based on 2010 data from the FBI, out of 8,775 firearm related murders, 358 were directly linked to rifles. 358 as a percentage of 8,775 is 4.1%.

Please justify banning something that is responsible for 4.1% of all firearms murders, and 2.7% of all murders? Knives were respionsible for 14% of ALL murders, 12,996. Hands fists and feet were responsible for 745 murders, about 5.7% of all murders.

http://www.fbi.gov/about-us/cjis/ucr/crime-in-the-u.s/2010/crime-in-the-u.s.-2010/tables/10tbl20.xls