An experiment that worked,

but was downright odd.

DISCLAIMER:
Yes, I used data from the Hodgdon reloading page.  Yes, worked in mine.  I can't guarantee anything for yours, these are just the results I got.

Loaded some subsonic ammo for 7.62x39 using the Hornady 255-grain Sub-X bullet first, using H4198 powder.  Since various of their other subsonic loads I'd tried in .308 ran hotter than their formula indicated, and I'd had that result in this cartridge using the Berry's 220-grain .308 bullet for .300 Blackout, I reduced the powder charge by a half a grain.  I'll note that other stuff I'd messed with, in the same rifle, the subsonics hit about 1.5" below standard loads, which- it being zeroed at 100 yards- were about two  inches low at 25 yards.  I got this

All nicely subsonic, and way higher point of impact.  Hm.

Second test, same rifle, was using some X-Treme .308 bullets of 125 grains.  I'd slugged the bore, and best I could tell this would fit pretty well, so worth a try.  These were loaded with the starting load at that bullet weight of 24.5 H4198.  And got this:

Velocities a touch above 2000fps, which is about one hundred fps slower than the load page showed for that weight with a .310 bullet.  And even higher than the other load.

And just to try it, I fired a few with some PMC factory ammo, and the scope still had them hitting at the original POI.

Folks, this is just weird, but with accuracy like that I'm going to go with it, and try some more of both.  The subsonic I'll up the charge a bit to see if can get the 1067 their page shows.  We shall see.