If you can only have one rifle, a .308 is probably the best all-around choice. However, if you are worried about home defense right now, rather than just in case of TEOTWAWKI, a .223 rifle is very appealing. If funds allow, it might be useful to get a rifle in each caliber. To avoid the need to learn two completely different rifles, the best
option may be to purchase the same design in both calibers. Several weapon systems [allowing commonality of training] are available for both rounds, including the AR-10/AR-15 and the HK91/HK93.
Most of the technical information given above comes from
www.ammo-oracle.com. For those who are interested in the subject, this site has an extremely thorough discussion of the ballistics and
wounding potential of the .223 round.
I would have to agree on the 5.56 ammo. If you are shooting either the m193 55gr. or the SS109 62gr. as long as the bullet velocity is maintained above 2700fps then there is dramatic fragmentation. This is due to the military cannelure, when the bullet enters flesh it starts to yaw (tumble) once the bullet reaches 90 degrees the jacket comes apart causing massive wound injuries. This is only true of military style ammo, not plinking ammo or wolf. I feel that the 5.56 is more effective then 308 at 200 yards or less, but after 200 yards I would only recommend the 308. I do not expect you to believe just me so go to
www.ammo-oracle.com or there is a link on
www.ar-15.com also. Another thing we must all take into consideration that the supply of surplus 308 is getting scarce and no major military is using it in mass quantities (that I am aware of) 5.56 is here to stay for a while and is readily available. In the event of a NATO or military invasion of US soil it is what the troops will be carrying so it would be nice to know that the enemies ammo can be used in our guns. Just a little food for thought. You also have to consider the surplus of 762x39 ammo, IMHO the 5.56 is stuck in the middle of the .308 and the 762X39.