well i dont know if you can shoot 223 in a 5.56 but if you can the i would go with fed. 64 gn soft point , fed. golddot 63gn or fed 60 vital-shok in that order and hornady 60gn TAP would be in there too.
when you start reloading i would try the 70gn sofl point or the speer 70 gn semi spitzer
if it where me i would have got a barrel in 223 with a 1-8 or 1-9 twist the 1-7 twist are for shooting the heavier match target bullets but you should be ok with it.
