I watched the recently published youtube video yesterday for CCI small pistol, small pistol magnum and small rifle. The pressure data showed there was really no significant different from that perspective. It's the cup thickness that seems to be the main difference and the guy doing the video says they load with them interchangeably and the only issue is if your gun will set them off for pistol use. Of course it would be bad to try loading a rifle with a soft pistol primer unless you were shooting "gopher" loads at reduced pressure and velocity but no danger substituting rifle primers in pistol loads.