Loved the November issue, especially the article where they went through Urban Rifle with a .30-30 (especially since I had a partial hand in giving the folks the idea for that article on this very forum).
One thing, though. In Denny's briefing, he says that "a .223 has significantly less penetration than 9mm ball fired from a handgun."
In my experience in owning two AR-15s and shooting M16s in the military, this simply hasn't been the case. .223 55grn FMJ (like South African surplus), in my experience, simply doesn't fragment as well as its proponents think it will. I've shot thorugh both sides of a steel GI helmet and a 55 gallon drum, and I don't think the bullet slowed down much. There was a clean entry hole and a clean, slightly larger exit hole, and no signs of fragmentation. Thus, from my own experience, I wouldn't bet on a .223 FMJ round (leaving the barrel at 3,000 feet per second) fragmenting when hitting wall board or drywall.
Also note that .223 will slide through a soft armor vest easily, whereas 9mm will not.
However, this has been a topic of signifcant discussion on TFL. Many members have opinions, few have actually done tests.
This is where I think SWAT should step in. Perhaps they could settle it "once and for all"? I'm imagining a test where they build mockups of common house walls, such as brick, drywall, sheetrock, 2x4s, etc. Then, take various handgun rounds, (FMJ and JHP), as well as some rifle rounds (.223, 7.62x39, .308, .30-30) and see what kind of penetration you get with various loads.
To me, this would be an extemely interesting article, though it'd probably be difficult to put together the test.
Just an idea.