as stated the 38 S&W is larger in dia than the 38 spl by quite a bit,a fired 38 s&w case is.388 where a fired 38spl is.376, so you can see that we have a diff of .012 thousands of an inch,lots of room to expand,if you only load bp in the case's i would think you would be ok,but if you load smokeless then ya got trouble.starline makes brass for the 38(think midway has it)and due to the popularty of cowboy action shooting there are plenty of bullet mfgs that make the right dia(.361) bullets for it,i got some from a guy in missouri as i plan to load for my victory mdl