The .38 S&W and .38 Short Colt are similar in size, but there are minor differences in case thicknesses and capacities and in factory pressure levels.

However, since you are shooting them out of a model 10, you shouldn't have any problems with the 2.8 grains of Unique. I had loaded several hundred rounds for a guy several years ago but the only place I recorded the data was on the boxes he took. I think I used Bullseye for his anyway. I wish I could have been more help.