Gi specs. usually call for about 5gr. of a fast powder. Military use to use two powders, neither of which are cannester grade and avaialable to reloaders...SR7970 (which is a single based powder) and HPC 1 (which is a double based powder).
Goal was 855fps +/- 25FPS. Only "trick" ws that the military tested at the odd distance of 25.5feet (and they still may be testing from that distance for all I know).
For the last 30 years, have been using the basic 230gr. FMJ and 5.0gr. of Bullseye (but mostly using a home cast 230gr. with the same charge). Some manuals will go to 5.2 or 5.3, and you'd proably have to go that extra 2/10ths or so to get up to 850-870fps as 5.0 only averages 830fps.
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Can consider this a factoid:
As cases are reloaded, they tend to LOOSE velocity. Isn't a whole bunch, but is measureable. More or less evens out after 5 or so reloads. In NEW cases 9which are nicely tempered and grip the bullet well) will get the bove mentioned 830fps. In many times fired cases, make that 812fps.
The case mouth just gets harder and less ductile...is more "springy" so it releases the bullet a bit earlier, which accounts for the difference in vel.