I bought a newer production like new REBCG to put into my 12.5" ODG build this summer. I just received another very low round count used REBCG (both from EE) today for my 10.3" ODG build (also just a new received a 10.3" barrel from Primary Arms for it). The first one has a standard shaped cam pin. The one I received today has an asymmetrical shape with an arrow and the word muzzle engraved on it.
I found an archived thread from a little over a year ago where @GACS says to only use the asymmetrical cam pin in tabbed super duty uppers. Is that still the case? My 12.5 has blem receivers and rail (tabbed from July 4th sale), and the 10.3 had non blem receivers with a blem Mk14 rail. The plan was to put the REBCG I received today into the 10.3, but I'll swap them if needed.