I did a lot of Ransom Rest testing of Hardball loads last summer. The most accurate load I found for 230 gr FMJ was 4.6 grains of Bullseye which gave me a 2.6" group at 50 yards. If you throw out three flyers, the other 7 shots were inside of 1 1/2". Average velocity was 744 fps. Testing was done with Hornady FMJ.
Just for the record, Factory Federal Gold Match gave me a 7" group from the same gun. Avg Vel. was 891 fps
Had some vintage Olin Military Match ammo that gave me a 3 1/2" group with an Avg Vel of 865 fps
My Lyman Reloading manual had 4.7 grains of 700X as the Accuracy load. With that load I got an 8 1/2" group with an Avg. Vel. of 829 fps.
I don't shoot FMJ 200 SWC's, I use cast lead 200 grain SWC's. For that I prefer 4.1 grains of bullseye.
All testing done from Ransom Rest at 50 yards. The loads were tested in an accurized gun with a Kart barrel, your milage may vary.