I've had good luck, with very uniform velocities using CFE Black. When reloading for the S & W M-53,chambered for the 22 Rem. Jet cartridge.
Hopefully the 5.7 would also show promise, when using this powder? Unfortunately my stock of 40 grain "stubby" .22 bullets is exhausted. Because of this and the fire restrictions out in the forest. Have no way seeing if CFE Black would be a viable powder for the 5.7 X 28. Much smaller case capacity of the 5.7, might have a negative effect though?
My experience with faster burning powder, ( Longshot ). Has been quite negative. As the previous posters noted.