Yep, the Selector FSN 1005-587-8408 was normally(as if there is such a thing in the Military) originally issued to the Platoon Sargent. This pretty much stopped when the M-60 became available and the unit Armorer would then install the Selector as requested. I installed a number of them on Rifles(actually ALL of them) I provided to USMC units in the RVN. I did the same for the LRRP units who requested Rifles. I didn't have a problem with that.Used pinned loosely. They just didn't have them able to be full auto.