I didn't see the article and I don't actually know that much about the M4, but it's horses for courses...the more Compact M4 is a great tool in close combat arenas, it's primary use is not as a long range weapon, even though it is quoted as a 500m tool.
The AK 47 can't hit a barn door past 300 yards but it strikes me its pretty useful!
The 5.56 is an accomplished military round, it had issues in the early days, but changes were made, I don't believe we should be writing off the calibre because results from one make of rifle in some situations are not ideal, the 7.62 is not perfect, nei