4064 is bulky for a 223 neck.. and will fill up the case with about 25 grains.. and won't give max velocity, but it will give fair velocity and good accuracy...
H 380 is also a not commonly used powder in a 223, but is also very accurate...with velocity right around 3000 fps, regardless of bullet weight.. it is very low pressure with bullets whose weights are lighter than 60 grains..
4064 is one of my main "go to" powders for ANY 308 sized case, including the 243...
The others being IMR 4895, Varget, and RL 15, W 748....in similar burn rates...
This is with any sized bullets...
If I could only stock one powder for 22.250 and up, 4064, IMR 4895, RL 15, Varget or W 748 would be one of the picks...
