My 38-40 (a colt SAA) uses 180 grain lead (one reference gives a 175 grain data). If I were going the way of something not on the current tables...I'd just try some trail boss, iirc correctly trail boss gives some recommendations based upon case capacity when working up loads.
Buffalo Bore has 38-40 in 180 grains.
40S&W = 38-40 from my experience...those who do not read history, are doomed to repeat it...
