To me I would think the pressure could develop a problem if you were shooting these out of an actual gun designed for 38lc which would definately be a much older gun. If your using these in a 357 or 38 spl rated gun, I say go for it. Now if you were trying to develop a 38 lc +p+ round that might be different but it does not sound like that's what you are attempting. 2nd edition Lee manual lists 150 grain lead 2.3 to 2.8 min oal 1.390 at 755 fps or 2.6 to 3.3 HP38 at 777 150 grain lrn same min. Oal highest fps with universal 3.0 to 3.5.