SCP (SOTAR Cam Pin) is a collaboration between Chad Albrecht of School of American Rifle) and Forward Controls Design.
SCP features a machined dimple on one side of the carrier cam pin, so the user can always reinstall the cam pin on the carrier in the same orientation. Cam pin usually wears more heavily on one side, putting the cam pin in one direction, then another randomly creates uneven wear on the cam pin, and it becomes sloppy and loose in the bolt. When the cam pin is installed always facing the same direction, it leaves one side less worn and more intact, this has the effect of better maintaining a tight fit of the cam pin in the bolt, and reduces wear cam pin itself as well as on the cam pin bore on the bolt. Chad Albrecht is a well respected armorer and instructor, we saw what he has done on a few cam pins, and it piqued our interest. SCP is one of these "why didn't I think of it" moments for us, eminently simple and elegant, it's very much in line with our own design philosophy.
Chad Albrecht of SOTAR explains the benefits of reinstalling the cam pin in the same orientation in this video: https://youtu.be/VuZ4TgoR1Zk
SCP is based on the TDP spec cam pin, dimpled on one side, and NP3 or nitride coated. Indeed, the NP3 SCP is incorporated into the SBCG, starting from December, 2019 production units.