Trail Boss was developed for Cowboy Action Shooting, using "soft" lead bullets. When I first started loading sub sonic for my suppressed .44, Trail boss was recommended to me. I found I really could not get enough of it in a .44 case to propel a jacketed 300 gr bullet. Worked great with lead semi-wadcutters of 240 grs. With those at about 850 - 900 fps, it really is quieter than my pellet gun, although probably not a lot more lethal. After confirming Trail Boss was meant for lead only, I used Universal, then Tight Group for my sub sonic loads, and both work well with either hard cast of jacketed bullets.
Mike
