Well,one of my 223's that I use in the ground digger fields wears a Leupold 6.5-20X50 LR. Great scope and the side focus is very handy, but it's very pricey.
Another wears a Nikon Monarch 5.5-16.5X44 that is every bit as nice a scope for way less than half the cost of the LR.
And if you want to go the cheap route, might take a look at the Swift Premier. Have a couple of 4-12X40's that are a heck of a scope for $115.
HTH,
Ladobe