I think your load of 4.6 grs of 231 is fine. Speer #13 manual lists a load
of 4.5 grs at 998 fps with their 124 gr JHP. But obviously 231 is not the
best choice for velocity as Speer shows HS-7 at 1249 fps with 8.9 grs
and Blue Dot at 1238 fps with 7.9 grs.