I’ve used surplus powder from GI brass that was described as a flake version of 4759. In previous tests it appeared about 10% faster than regular IMR 4759 velocities.
Range test 03-21-19
Alexander Arms upper
MP 400 solid FNGC PC
CCI 350 Mag Pistol
26.0 flake surplus 4759...1631 fps.
COAL 2.00”
Bullet diameter .501”, PCed and Hornady GCs
Groups at 50 yards easily attained 1” and less.