I thought the same thing. The two "classic" loads for the .38 with a 148 wadcutter are either 2.7 of Bullseye for hollowbase wadcutters or 3.5 for double-enders. More powder gets you very little with these bullets, and can blow out the skirt if they're hollowbase wadcutters. Double-end wadcutters don't have that thin skirt and can be booted a bit harder. But neither wants to be launched at much over 700 fps.
My own favorite loads are built around 158 cast SWC bullets, cast soft. I use 3.5 grains of literally any powder from Bullseye through GreenDot and all of them work just fine. W231, RedDot, 700X, Solo 1000, Nitro 100, American Select, Clays and AA-2 have all gven me between 800 and 900 fps with these bullets in any gun I've tried.
Just my personal thought in this, but I think loading jacketed bullets in a .38 is just silly.
