Since nobody else has mentioned it yet, let me plug one of our fairly new powders for this application - AR-Comp(R).
AR-Comp is outstanding in both 223Rem and 308Win. It was originally designed for the M118LR application, and it delivers best in class efficiency, accuracy and temperature stability there. It also excels in 223Rem, up through 77gr or so. It ended up a little faster burning than Reloder(R) 15 and Varget, so it is very close to 4895 burn speed wise. At it's burn speed it doesn't deliver the absolute highest velocities, but you can do just fine at good pressures. If higher velocities are needed, you can go to the Reloder 15 speed offerings, or Power Pro(TM) 2000MR. The accuracy on AR-Comp is outstanding though (typically), which is usually more important than 30-50 additional ft/sec.
AR-Comp is not a spherical powder, but a stick powder the same basic size as Reloder 15, so it meters OK. It does also contain decoppering additives.
Shoot well,
Paul