I have read small pistol and small rifle primers are the same/interchangeable. I have also read your gonads would fall off and beagle puppies everywhere will die if you use the wrong primer.
I have used small rifle primers in all of my pistols, and a AR 9mm "pistol" with no problems. (Standard AR15 lower and parts) I have not tried small pistol primers in small rifle cases (yet). What do you think?