I think I posted on this before, but I couldn’t find it, and it is still an “Unknown”.
The projo is GMCS, with a faint red tip and black band. The base is closed with a copper cup. There are two knurls, one being wider than the other. The diameter between the knurls is 7.89mm/.310in., length is 28.6mm/1.126in., and the weight is 114.10grains. It appears to be some kind of East Bloc API bullet, but the weight seems to be too low. I got it mixed in with a bag of mixed 7.62x39 rounds, mainly different color tips, one of which was an unknown black tip pressure-test round.
Any thoughts or ideas?