I had the same outcome trying bayou, sns, black bullet and blue bullets in a 9mm open gun. A single double tap with a far enough transition wasn't bad, but the cmore would get pretty cloudy by the end of a 32 round stage (gun has 3 barrel holes).
Only using PD & MG JHPs now in the open gun.
Coated bullets in anything without a comp & optic - would probably be fine in a prod optics gun.