Reloading for Ruger sp101 38 spl

[ralph2]

I am looking at Rugers web page at the SP101 models ksp321xl (357 mag) and ksp821x (38 spl) and the only difference I can see with the 38 spl is it has a hammer spur and a shorter cylinder which is made up with an extended forcing cone. The question is what are the differences I can't see ? I am thinking the 38 spl version could be loaded to say super +p levels with no safety issues. I have a ton of 38 spl brass that I don't like to shoot in my 357 mag but would like to have a 38 spl that could take loads of 158 grain bullets at around 850-900fps vs around 700fps at 38spl levels.