For reference, I tested two new models, 637, both purchased the same day with a box of white box 38 Plus P 125 grain. The barrels are 1 7/8. One gun averaged 888 fps the other 913 fps, same ammo, same day.
So, a 2 inch get about 900 fps from the 125 grain white box which actually expands very well cheap ammo you can get anywhere.
I have tried lots of 38 and chose the Critical Defense for my wife to carry, but I do not care if the gun is a 38. I carried the J frame in harms way and in law enforcement as a primary and as a backup for many years and have finished of deer and shot lots of critters with the 38.
That said, at 38 velocities, I do not think it matters. Any 125 Plus P or any 158 grain load wadcutter or flat point bullet works for me. Those train and defend loads are great also.
If I want more, I have 2.5 and 3 inch guns in 357/,,