The following is what I've found to cycle well and shoot accurately in my Roth-Steyr pistol's.
The bullet is a 100g 8mm Lebel Total Metal Jacket .330" diameter. These are offered by Graff and Son's. I resized these bullets down to .324" diameter.
My load data...
Red Dot @ 3.3g
Graf & Son's Lebel 100g Tmj bullet (resized bullets down to .324" diameter)
Fiocchi 8mm Roth-Steyr brass
Measured Velocity 1090 FPS
Shoots consistent .5" to .75" 3 shot groups at 35 feet.