Generally slow burning powders ( 2400-296 range) do not work well in a 2" barrel as the bullet exits the barrel before the powder is consumed.. but if you want to also fry what you shoot at then that is a good solution.
In my 38 Specials with 2" barrels I generally look at Unique being about as slow a powder range as I care to work with. This is also with at least a 158 cast (I prefer a 165gr 40-1 bullet) as these heavier bullets let the powder get a good burn acomplished. For lighter bullets I turn to fast pistol / shotgun powders like Red Dot or 231.
High pressure can be accomplished with any powder... 231 can blow the top strap & cylinder top right off a revolver... the slower powders will give fast FPS with less pressure buildup over a longer period of time.. in millionths of seconds..
Mike in Peru