Can anyone tell me what the difference is between the hornady interlock SP and interlock SP-RP? Specially the .350 200gr version. The product number on the box is #3510, which when googled brings up the SP-RP. However the box label just says SP. Is there a difference, or were they just “renamed” at some point? I spent some time on google and didn’t see an answer, so figured someone here would know. The couple boxes I have are not the newest production, they’re the older red boxes with white writing on them.
