Glad you asked - I have a .395 Lyman mould that cases .398" X .398" = oversize. That also happens to be the bore size of my .40 cal Goodoien barrel = .398".
I also have a .400" DC Lyman mould that casts .400 X .400 from one cavity, but oblong POS from the other - .394" X .400"- useless for accuracy in my 50 yard tests. The .400" ball is very accurate with a .020" heavy pocket drill, tight weave patch. Due to the pain of using a DC mould and only filling one cavity, i use the .395" (.398"0 mould) due to it being easier to handle, weight wise.
The .398" ball loads quite easily with the .020" through to the .0235" patches - all shooting close enough to the sights that it matters not which material I have at hand. Once stated, they go down using only 2 fingers on the 3/8" hickory rod - BUT - you do have to actually grip the rod with those fingers and push the ball down in 10" to 14" stages.
When using LHV or Shenendoah lubes, I have to use 75gr. 3F GOEX or 85gr. 2F GOEX - number of shots without wiping is unlimited. I clean the barrel at the end of the day, never having to wipe it while shooting. As with all my rifles, they've never fired a shot with any phony powder. Perhaps that is why they shine like the sun, inside. When using water based lube, I can cut those charges back to 60 to 65gr. of either, 3F or 2F GOEX.