For any new AR15 gun owners out there wanting to know the difference between the .223 Rem and 5.56 NATO cartridges. The video briefly discuss the differences and whether or not they are interchangeable to be fired from whatever chambered AR15 one has bought. The video is basic, but a good explanation for new AR15 owner that may want to research the topic further.
Video: Is .223 or 5.56 Better?
www.classicfirearms.com