Yes, LP and LR primers will physically interchange. They are of the same dimensions.
Small Pistol primers have a shorter cup than Small Rifle primers.
Powder suggestion for those reduced velocity loads. I really like Titegroup for this application in 41 mag and 327 Fed reduced velocity loads. Beware, it will use a small volume of case capacity and can be easily double charged.
Since the Biden primer shortage of this past year I have used up all of my SP primers and have had to dip into my SR primer supply for pistol primers.
I have loaded and shot at least 1000 SR primers in .38 Spl for my S&W revolvers and 9 mm in my Kimber and Springfield Armory pistols without any problems.
