Sort of. Then again, if you use the wrong .223 ammo with the .223 ACOG, you will have problems as well. As I recall, the .223 ACOGs are calibrated for M855 62 gr. ammo fired from a 14.5" barrel
The question is, just how accurate do you want to be. The problem is that .308 and .223 don't have the same ballistics and the differences become more and more dramatic with distance. Depending on the ammo, you might be fine out to 200-300 yards with a reasonable amount of error.