[FromTheSidelines]

If you're not sure about the power of the 5.56, I'd suggest this set of tests from The Box O Truth. Especially the destruction wrought by that little 5.56mm bullet even after penetrating 30 sheets of Kevlar:

If you want 308 because you don't think 5.56 is deadly enough, you might want to reconsider. If you want 308 because you want the ability to reliably reach out and shoot 500+ yards, then you're going right. But for "close in" work against things that walk on 2 legs, the little 5.56mm is a very good option.

[West Texas Chuck]

People keep telling me this, maybe I should drop my notions about that round.

I guess I am being prejudiced. Like I said, I know little of this arena of the firearms world.

[Spktyr]

Sadly, 5.56 is marginal for Texas feral pig.

[Spktyr]

And I’m talking about the kind that go ‘oink’ and walk about on all fours while sporting tusks, that kind of pig.

[jboot]

Although I am not convinced that there is any degree of parity between the 5.56 and the .308, I selected 5.56 for my SHTF gun because it will be the cartridge of my opponent. If the worst happens .308 (and 7.62x39 Russki) will be thin on the ground but 5.56 will be everywhere. And remember, your semi-auto SHTF gun is just a tool to get a BETTER gun, a selective fire gun, which in most cases will be an M4. It is merely sensible to have cartridges and mags that fit the M4 already on hand in quantity.