Wondering what your take on this discussion might be? The M-16 and its 5.56 round are taking some hits on this thread, but with no real consensus on what makes a good replacement.
I use an old AR-15 in 5.56, or sometimes a mini 14 for a boat gun, mainly because I thought they look intimidating, and I didn't really want to take my .270 out to sea either. Plus, I like the idea of 30 round clips.
I don't really care for 5.56... there are better options with 6.5 x .308, 6.5 PPC, 6.8 SPC...
There are plenty of M-14 variants out today, and 7.62x51 is a proven performer...
I say it's time to move on from 5.56...