I've found 3031 excellent in 223,
I had a very accurate load in my Tikka T3 using the 69g Sierra.
Also worked Very well for me in AR carbines.
It's a bit too fast to cycle a 20" rifle, so it was tricky.
Shot a lot of 55g FMJ using 24g.
It actually an ideal powder for 223, burns very efficient according to quick load.