It's not difficult to get at or near-.38-44 performance (around 1100 ft/sec) from any of the mid- or slow powders using 158 grain lead SWC bullets. The old Lyman handbooks contain such recipes using both Unique and 2400. I used one of the really old Phil Sharpe .38-44 recipes (10 grains of duPont SR 80 bulk powder, long obsolete, replaced by SR 4759) and was getting around 1100 ft/sec, chronographed from from my Combat Masterpiece. All these loads were considered safe to use in any .38 Special revolver back in the day, and that should still be the case.

Sharpe's top Unique load was 6.6 grains with a 158 grain bullet, MV from a 6" barrel given to be 1130 ft/sec.